From 20a731b6e8090a3a97c0020edaa196ff7d5d2a6c Mon Sep 17 00:00:00 2001
From: Michael Neale <michael.neale@gmail.com>
Date: Tue, 11 Aug 2026 16:19:44 +1000
Subject: [PATCH] fix(desktop): admit buzz_agent logs to per-agent log files

buzz-acp inherits its stderr to the agent subprocess (acp.rs:463), so the
desktop's RUST_LOG filter for the harness also decides what the agent can
write to disk. It named only buzz_acp, so every buzz-agent diagnostic was
filtered out before reaching the per-agent log.

That is invisible until something goes wrong: an agent misbehaving in the
desktop left no trace of compaction, the _Stop veto, max-rounds, or
provider errors -- exactly the lines you need to tell whether a turn did
what it should. Found while trying to confirm from the logs alone that a
desktop agent was running the new loop; the logs could not answer it.

Adds buzz_agent=info to the default, appends only the missing directive
when an operator filter is present (so RUST_LOG=buzz_agent=debug is not
downgraded to info), and takes a fully-specified filter verbatim.

Co-authored-by: Michael Neale <michael.neale@gmail.com>
Signed-off-by: Michael Neale <michael.neale@gmail.com>
---
 crates/buzz-agent/src/lib.rs                  |  14 +-
 crates/buzz-model-catalog/src/lib.rs          |  27 +
 desktop/src-tauri/Cargo.lock                  | 692 ++++++++++++++++--
 .../src-tauri/src/managed_agents/runtime.rs   |  85 ++-
 4 files changed, 760 insertions(+), 58 deletions(-)

diff --git a/crates/buzz-agent/src/lib.rs b/crates/buzz-agent/src/lib.rs
index aacdf392e6..073ce8c7f7 100644
--- a/crates/buzz-agent/src/lib.rs
+++ b/crates/buzz-agent/src/lib.rs
@@ -1055,23 +1055,11 @@ pub fn run() -> Result<(), Box<dyn std::error::Error>> {
 /// The cached token is what lets both the agent loop and the desktop model
 /// picker work without a static `DATABRICKS_TOKEN`.
 async fn auth_subcommand(args: &[String]) -> Result<(), Box<dyn std::error::Error>> {
-    use buzz_model_catalog::auth::{PkceOAuthConfig, PkceOAuthTokenSource};
-
     match args.first().map(String::as_str) {
         Some("databricks" | "databricks_v2" | "databricks-v2") => {
             let host = std::env::var("DATABRICKS_HOST")
                 .map_err(|_| "auth databricks: DATABRICKS_HOST required")?;
-            let pkce = PkceOAuthConfig {
-                discovery_url: format!(
-                    "{}/oidc/.well-known/oauth-authorization-server",
-                    host.trim_end_matches('/')
-                ),
-                client_id: "databricks-cli".into(),
-                scopes: vec!["all-apis".into(), "offline_access".into()],
-                cache_namespace: "databricks".into(),
-                cache_dir_override: None,
-            };
-            PkceOAuthTokenSource::new(pkce)?.interactive_login().await?;
+            buzz_model_catalog::authenticate_databricks(&host).await?;
             eprintln!("Authenticated. Token cached under ~/.config/buzz-agent/oauth/databricks/.");
             Ok(())
         }
diff --git a/crates/buzz-model-catalog/src/lib.rs b/crates/buzz-model-catalog/src/lib.rs
index 1b4b796769..1a4e8da400 100644
--- a/crates/buzz-model-catalog/src/lib.rs
+++ b/crates/buzz-model-catalog/src/lib.rs
@@ -22,6 +22,33 @@ pub use catalog::{discover_databricks_models, ModelEntry, DATABRICKS_V2_KNOWN_MO
 pub use config::{Config, Provider};
 pub use types::AgentError;
 
+/// PKCE configuration for Databricks OAuth against `host`.
+///
+/// Shared so the desktop model picker and `buzz-agent auth databricks` cache
+/// tokens in the same place.
+pub fn databricks_pkce_config(host: &str) -> auth::PkceOAuthConfig {
+    auth::PkceOAuthConfig {
+        discovery_url: format!(
+            "{}/oidc/.well-known/oauth-authorization-server",
+            host.trim_end_matches('/')
+        ),
+        client_id: "databricks-cli".into(),
+        scopes: vec!["all-apis".into(), "offline_access".into()],
+        cache_namespace: "databricks".into(),
+        cache_dir_override: None,
+    }
+}
+
+/// Run the interactive Databricks OAuth PKCE login and cache the token.
+///
+/// Needs a browser on the machine. The desktop model picker calls this when
+/// discovery fails with an auth error.
+pub async fn authenticate_databricks(host: &str) -> Result<(), AgentError> {
+    auth::PkceOAuthTokenSource::new(databricks_pkce_config(host))?
+        .interactive_login()
+        .await
+}
+
 /// Environment keys the Windows Git Bash resolver may inspect.
 ///
 /// The MCP child is spawned with an otherwise-cleared environment, so every
diff --git a/desktop/src-tauri/Cargo.lock b/desktop/src-tauri/Cargo.lock
index 65ee82e9e1..2e5f7fb7d0 100644
--- a/desktop/src-tauri/Cargo.lock
+++ b/desktop/src-tauri/Cargo.lock
@@ -84,6 +84,7 @@ dependencies = [
  "cfg-if 1.0.4",
  "getrandom 0.3.4",
  "once_cell",
+ "serde",
  "version_check",
  "zerocopy",
 ]
@@ -97,6 +98,30 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "alacritty_terminal"
+version = "0.26.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bda177466b9524d59f1b12f0dd30b68696788e9992a7e959021c4a0ed96fcf59"
+dependencies = [
+ "base64 0.22.1",
+ "bitflags 2.13.0",
+ "home",
+ "libc",
+ "log",
+ "miow",
+ "parking_lot",
+ "piper",
+ "polling",
+ "regex-automata",
+ "rustix 1.1.4",
+ "rustix-openpty",
+ "signal-hook 0.4.4",
+ "unicode-width 0.2.2",
+ "vte 0.15.0",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "alloc-no-stdlib"
 version = "2.0.4"
@@ -707,6 +732,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fd307490d624467aa6f74b0eabb77633d1f758a7b25f12bceb0b22e08d9726f6"
 
+[[package]]
+name = "base64"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e1b586273c5702936fe7b7d6896644d8be71e6314cfe09d3167c95f712589e8"
+
 [[package]]
 name = "base64"
 version = "0.21.7"
@@ -731,6 +762,12 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32637268377fc7b10a8c6d51de3e7fba1ce5dd371a96e342b34e6078db558e7f"
 
+[[package]]
+name = "beef"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a8241f3ebb85c056b509d4327ad0358fbbba6ffb340bf388f26350aeda225b1"
+
 [[package]]
 name = "bip39"
 version = "2.2.2"
@@ -999,7 +1036,7 @@ dependencies = [
 
 [[package]]
 name = "buzz-desktop"
-version = "0.5.2"
+version = "0.5.9"
 dependencies = [
  "anyhow",
  "arboard",
@@ -1007,11 +1044,14 @@ dependencies = [
  "audioadapter-buffers",
  "axum",
  "base64 0.22.1",
+ "block2",
  "buzz-core",
  "buzz-media",
  "buzz-model-catalog",
  "buzz-persona",
  "buzz-sdk",
+ "buzz-terminal",
+ "buzz-voice",
  "bytes",
  "bzip2 0.6.1",
  "chrono",
@@ -1040,9 +1080,11 @@ dependencies = [
  "objc2",
  "objc2-app-kit",
  "objc2-foundation",
+ "objc2-user-notifications",
  "opus",
  "plist",
  "png 0.18.1",
+ "portable-pty",
  "regex",
  "reqwest 0.13.4",
  "rodio",
@@ -1068,6 +1110,7 @@ dependencies = [
  "tauri-plugin-single-instance",
  "tauri-plugin-updater",
  "tauri-plugin-window-state",
+ "tauri-utils",
  "tempfile",
  "tokio",
  "tokio-tungstenite 0.29.0",
@@ -1121,6 +1164,7 @@ dependencies = [
  "async-trait",
  "axum",
  "base64 0.22.1",
+ "dirs",
  "getrandom 0.4.3",
  "hex",
  "reqwest 0.13.4",
@@ -1155,6 +1199,34 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "buzz-terminal"
+version = "0.1.0"
+dependencies = [
+ "alacritty_terminal",
+ "libc",
+ "parking_lot",
+ "portable-pty",
+]
+
+[[package]]
+name = "buzz-voice"
+version = "0.1.0"
+dependencies = [
+ "atomic-write-file",
+ "hex",
+ "ort",
+ "ort-sys",
+ "rand 0.10.2",
+ "sentencepiece-model",
+ "serde",
+ "serde_json",
+ "sha2 0.11.0",
+ "sherpa-onnx",
+ "symphonia",
+ "tokenizers",
+]
+
 [[package]]
 name = "by_address"
 version = "1.2.1"
@@ -1353,6 +1425,12 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
+
 [[package]]
 name = "cfg_aliases"
 version = "0.2.1"
@@ -1557,6 +1635,7 @@ dependencies = [
  "itoa",
  "rustversion",
  "ryu",
+ "serde",
  "static_assertions",
 ]
 
@@ -1808,6 +1887,16 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5181e0de7b61eb03a81e347d6dd8797bae9da5146707b51077e2d71a54ec0ceb"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-epoch"
 version = "0.9.20"
@@ -1834,7 +1923,7 @@ dependencies = [
  "mio",
  "parking_lot",
  "rustix 0.38.44",
- "signal-hook",
+ "signal-hook 0.3.18",
  "signal-hook-mio",
  "winapi",
 ]
@@ -1852,7 +1941,7 @@ dependencies = [
  "mio",
  "parking_lot",
  "rustix 1.1.4",
- "signal-hook",
+ "signal-hook 0.3.18",
  "signal-hook-mio",
  "winapi",
 ]
@@ -2019,6 +2108,12 @@ dependencies = [
  "cmov",
 ]
 
+[[package]]
+name = "cursor-icon"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f27ae1dd37df86211c42e150270f82743308803d90a6f6e6651cd730d5e1732f"
+
 [[package]]
 name = "curve25519-dalek"
 version = "4.1.3"
@@ -2132,6 +2227,15 @@ dependencies = [
  "syn 2.0.118",
 ]
 
+[[package]]
+name = "dary_heap"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b1e3a325bc115f096c8b77bbf027a7c2592230e70be2d985be950d3d5e60ebe"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "dasp_sample"
 version = "0.11.0"
@@ -2528,7 +2632,7 @@ dependencies = [
  "rustc_version",
  "toml 1.1.2+spec-1.1.0",
  "vswhom",
- "winreg",
+ "winreg 0.55.0",
 ]
 
 [[package]]
@@ -2629,6 +2733,12 @@ version = "3.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dea2df4cf52843e0452895c455a1a2cfbb842a1e7329671acf418fdc53ed4c59"
 
+[[package]]
+name = "esaxx-rs"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d817e038c30374a4bcb22f94d0a8a0e216958d4c3dcde369b1439fec4bdda6e6"
+
 [[package]]
 name = "euclid"
 version = "0.22.14"
@@ -2687,6 +2797,17 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "fancy-regex"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e24cb5a94bcae1e5408b0effca5cd7172ea3c5755049c5f3af4cd283a165298"
+dependencies = [
+ "bit-set 0.8.0",
+ "regex-automata",
+ "regex-syntax",
+]
+
 [[package]]
 name = "fast-srgb8"
 version = "1.0.0"
@@ -4190,7 +4311,7 @@ dependencies = [
  "backon",
  "blake3",
  "bytes",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "ctutils",
  "data-encoding",
  "derive_more",
@@ -4258,7 +4379,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "516e4eedc38e33ab69a6bd325520332dc3d67b25454e2d590ebb84a25240dd9a"
 dependencies = [
  "arc-swap",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "derive_more",
  "hickory-resolver",
  "iroh-base",
@@ -4310,7 +4431,7 @@ checksum = "8149bb6a57126225a07d6928846d82dcedfd24ea0f863ef7b2eb475e1d726354"
 dependencies = [
  "blake3",
  "bytes",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "data-encoding",
  "derive_more",
  "getrandom 0.4.3",
@@ -4758,6 +4879,39 @@ version = "0.4.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ceec5bc11778974d1bcb055b18002eba7f4b3518b6a0081b3af5f21666da9ad"
 
+[[package]]
+name = "logos"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7251356ef8cb7aec833ddf598c6cb24d17b689d20b993f9d11a3d764e34e6458"
+dependencies = [
+ "logos-derive",
+]
+
+[[package]]
+name = "logos-codegen"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59f80069600c0d66734f5ff52cc42f2dabd6b29d205f333d61fd7832e9e9963f"
+dependencies = [
+ "beef",
+ "fnv",
+ "lazy_static",
+ "proc-macro2",
+ "quote",
+ "regex-syntax",
+ "syn 2.0.118",
+]
+
+[[package]]
+name = "logos-derive"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24fb722b06a9dc12adb0963ed585f19fc61dc5413e6a9be9422ef92c091e731d"
+dependencies = [
+ "logos-codegen",
+]
+
 [[package]]
 name = "loom"
 version = "0.7.2"
@@ -4867,6 +5021,22 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "macro_rules_attribute"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3ae8f6d608c795738406608304d30a2dfbdc8e58e44f7ba43236da5208ded3c"
+dependencies = [
+ "macro_rules_attribute-proc_macro",
+ "pastey",
+]
+
+[[package]]
+name = "macro_rules_attribute-proc_macro"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc04a4c58212d57930a24bf47d3fa87485264a3a054e9c10e042eb373573ad3c"
+
 [[package]]
 name = "markup5ever"
 version = "0.38.0"
@@ -4893,6 +5063,16 @@ version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47e1ffaa40ddd1f3ed91f717a33c8c0ee23fff369e3aa8772b9605cc1d22f4c3"
 
+[[package]]
+name = "matrixmultiply"
+version = "0.3.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f607c237553f086e7043417a51df26b2eb899d3caff94e6a67592ff992fedc7"
+dependencies = [
+ "autocfg",
+ "rawpointer",
+]
+
 [[package]]
 name = "maybe-async"
 version = "0.2.11"
@@ -4992,7 +5172,7 @@ dependencies = [
  "mesh-llm-types",
  "model-artifact",
  "nostr-sdk",
- "prost",
+ "prost 0.14.4",
  "rand 0.10.2",
  "rustls",
  "serde",
@@ -5130,7 +5310,7 @@ dependencies = [
  "opentelemetry",
  "opentelemetry-otlp",
  "opentelemetry_sdk",
- "prost",
+ "prost 0.14.4",
  "rand 0.10.2",
  "regex-lite",
  "reqwest 0.12.28",
@@ -5219,8 +5399,8 @@ source = "git+https://github.com/Mesh-LLM/mesh-llm.git?tag=v0.74.0#e60b2fe43aa05
 dependencies = [
  "anyhow",
  "async-trait",
- "prost",
- "prost-build",
+ "prost 0.14.4",
+ "prost-build 0.14.4",
  "protoc-bin-vendored",
  "rmcp",
  "schemars 1.2.1",
@@ -5256,7 +5436,7 @@ dependencies = [
  "anyhow",
  "hex",
  "iroh",
- "prost",
+ "prost 0.14.4",
  "serde_json",
  "sha2 0.10.9",
 ]
@@ -5371,6 +5551,28 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "miette"
+version = "7.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f98efec8807c63c752b5bd61f862c165c115b0a35685bdcfd9238c7aeb592b7"
+dependencies = [
+ "cfg-if 1.0.4",
+ "miette-derive",
+ "unicode-width 0.1.14",
+]
+
+[[package]]
+name = "miette-derive"
+version = "7.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db5b29714e950dbb20d5e6f74f9dcec4edbcc1067bb7f8ed198c097b8c1a818b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.118",
+]
+
 [[package]]
 name = "mime"
 version = "0.3.17"
@@ -5430,6 +5632,15 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "miow"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "536bfad37a309d62069485248eeaba1e8d9853aaf951caaeaed0585a95346f08"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "model-artifact"
 version = "0.74.0"
@@ -5516,6 +5727,28 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "monostate"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3341a273f6c9d5bef1908f17b7267bbab0e95c9bf69a0d4dcf8e9e1b2c76ef67"
+dependencies = [
+ "monostate-impl",
+ "serde",
+ "serde_core",
+]
+
+[[package]]
+name = "monostate-impl"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e4db6d5580af57bf992f59068d4ea26fd518574ff48d7639b255a36f9de6e7e9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.118",
+]
+
 [[package]]
 name = "more-asserts"
 version = "0.3.1"
@@ -5600,7 +5833,7 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2ab99dfb861450e68853d34ae665243a88b8c493d01ba957321a1e9b2312bbe"
 dependencies = [
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "derive_more",
  "futures-buffered",
  "futures-lite",
@@ -5643,6 +5876,21 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "ndarray"
+version = "0.17.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "520080814a7a6b4a6e9070823bb24b4531daac8c4627e08ba5de8c5ef2f2752d"
+dependencies = [
+ "matrixmultiply",
+ "num-complex",
+ "num-integer",
+ "num-traits",
+ "portable-atomic",
+ "portable-atomic-util",
+ "rawpointer",
+]
+
 [[package]]
 name = "ndk"
 version = "0.9.0"
@@ -5775,7 +6023,7 @@ checksum = "4d9cbe01741347ef750d743d6690603f5eed8341e679fb51c8e629337aa11976"
 dependencies = [
  "atomic-waker",
  "bytes",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "derive_more",
  "ipnet",
  "js-sys",
@@ -5810,6 +6058,18 @@ version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "650eef8c711430f1a879fdd01d4745a7deea475becfb90269c06775983bbf086"
 
+[[package]]
+name = "nix"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
+dependencies = [
+ "bitflags 2.13.0",
+ "cfg-if 1.0.4",
+ "cfg_aliases 0.1.1",
+ "libc",
+]
+
 [[package]]
 name = "nix"
 version = "0.29.0"
@@ -5818,7 +6078,7 @@ checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
 dependencies = [
  "bitflags 2.13.0",
  "cfg-if 1.0.4",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "libc",
  "memoffset",
 ]
@@ -5831,7 +6091,7 @@ checksum = "74523f3a35e05aba87a1d978330aef40f67b0304ac79c1c00b294c9830543db6"
 dependencies = [
  "bitflags 2.13.0",
  "cfg-if 1.0.4",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "libc",
 ]
 
@@ -5843,7 +6103,7 @@ checksum = "cf20d2fde8ff38632c426f1165ed7436270b44f199fc55284c38276f9db47c3d"
 dependencies = [
  "bitflags 2.13.0",
  "cfg-if 1.0.4",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "libc",
 ]
 
@@ -5873,7 +6133,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4bf95190af1bd4a00a10e8255ca0c8ddd9e9a9f5e79151d7a7eb6d56aff5dc89"
 dependencies = [
  "bytes",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "derive_more",
  "noq-proto",
  "noq-udp",
@@ -5921,7 +6181,7 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3137a52df66c20090a889828d1c655f21f52294cba64e5c4fbb04fc83eee7c8e"
 dependencies = [
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "libc",
  "socket2",
  "tracing",
@@ -6144,7 +6404,7 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "680998035259dcfcafe653688bf2aa6d3e2dc05e98be6ab46afb089dc84f1df8"
 dependencies = [
- "proc-macro-crate 2.0.2",
+ "proc-macro-crate 3.5.0",
  "proc-macro2",
  "quote",
  "syn 2.0.118",
@@ -6459,6 +6719,8 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9df9128cbbfef73cda168416ccf7f837b62737d748333bfe9ab71c245d76613e"
 dependencies = [
+ "bitflags 2.13.0",
+ "block2",
  "objc2",
  "objc2-foundation",
 ]
@@ -6624,7 +6886,7 @@ dependencies = [
  "opentelemetry-http",
  "opentelemetry-proto",
  "opentelemetry_sdk",
- "prost",
+ "prost 0.14.4",
  "reqwest 0.12.28",
  "thiserror 2.0.18",
 ]
@@ -6639,7 +6901,7 @@ dependencies = [
  "const-hex",
  "opentelemetry",
  "opentelemetry_sdk",
- "prost",
+ "prost 0.14.4",
  "serde",
  "serde_json",
  "tonic",
@@ -6705,6 +6967,24 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "ort"
+version = "2.0.0-rc.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7de3af33d24a745ffb8fab904b13478438d1cd52868e6f17735ef6e1f8bf133"
+dependencies = [
+ "ndarray",
+ "ort-sys",
+ "smallvec",
+ "tracing",
+]
+
+[[package]]
+name = "ort-sys"
+version = "2.0.0-rc.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7b497d21a8b6fbb4b5a544f8fadb77e801a09ae0add9e411d31c6f89e3c1e90"
+
 [[package]]
 name = "os_pipe"
 version = "1.2.3"
@@ -6932,6 +7212,16 @@ dependencies = [
  "pest",
 ]
 
+[[package]]
+name = "petgraph"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3672b37090dbd86368a4145bc067582552b29c27377cad4e0a306c97f9bd7772"
+dependencies = [
+ "fixedbitset 0.5.7",
+ "indexmap 2.14.0",
+]
+
 [[package]]
 name = "petgraph"
 version = "0.8.3"
@@ -7196,6 +7486,36 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "portable-atomic-util"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2a106d1259c23fac8e543272398ae0e3c0b8d33c88ed73d0cc71b0f1d902618"
+dependencies = [
+ "portable-atomic",
+]
+
+[[package]]
+name = "portable-pty"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4a596a2b3d2752d94f51fac2d4a96737b8705dddd311a32b9af47211f08671e"
+dependencies = [
+ "anyhow",
+ "bitflags 1.3.2",
+ "downcast-rs",
+ "filedescriptor",
+ "lazy_static",
+ "libc",
+ "log",
+ "nix 0.28.0",
+ "serial2",
+ "shared_library",
+ "shell-words",
+ "winapi",
+ "winreg 0.10.1",
+]
+
 [[package]]
 name = "portmapper"
 version = "0.19.1"
@@ -7406,6 +7726,16 @@ dependencies = [
  "unarray",
 ]
 
+[[package]]
+name = "prost"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2796faa41db3ec313a31f7624d9286acf277b52de526150b7e69f3debf891ee5"
+dependencies = [
+ "bytes",
+ "prost-derive 0.13.5",
+]
+
 [[package]]
 name = "prost"
 version = "0.14.4"
@@ -7413,7 +7743,27 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "528ac67416ff8646872a3c02cad9cc4ee5dc9f9540c9b10771855c95cb2e5ae1"
 dependencies = [
  "bytes",
- "prost-derive",
+ "prost-derive 0.14.4",
+]
+
+[[package]]
+name = "prost-build"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be769465445e8c1474e9c5dac2018218498557af32d9ed057325ec9a41ae81bf"
+dependencies = [
+ "heck 0.5.0",
+ "itertools",
+ "log",
+ "multimap",
+ "once_cell",
+ "petgraph 0.7.1",
+ "prettyplease",
+ "prost 0.13.5",
+ "prost-types 0.13.5",
+ "regex",
+ "syn 2.0.118",
+ "tempfile",
 ]
 
 [[package]]
@@ -7426,15 +7776,28 @@ dependencies = [
  "itertools",
  "log",
  "multimap",
- "petgraph",
+ "petgraph 0.8.3",
  "prettyplease",
- "prost",
- "prost-types",
+ "prost 0.14.4",
+ "prost-types 0.14.4",
  "regex",
  "syn 2.0.118",
  "tempfile",
 ]
 
+[[package]]
+name = "prost-derive"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a56d757972c98b346a9b766e3f02746cde6dd1cd1d1d563472929fdd74bec4d"
+dependencies = [
+ "anyhow",
+ "itertools",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.118",
+]
+
 [[package]]
 name = "prost-derive"
 version = "0.14.4"
@@ -7448,13 +7811,35 @@ dependencies = [
  "syn 2.0.118",
 ]
 
+[[package]]
+name = "prost-reflect"
+version = "0.14.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b5edd582b62f5cde844716e66d92565d7faf7ab1445c8cebce6e00fba83ddb2"
+dependencies = [
+ "logos",
+ "miette",
+ "once_cell",
+ "prost 0.13.5",
+ "prost-types 0.13.5",
+]
+
+[[package]]
+name = "prost-types"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52c2c1bf36ddb1a1c396b3601a3cec27c2462e45f07c386894ec3ccf5332bd16"
+dependencies = [
+ "prost 0.13.5",
+]
+
 [[package]]
 name = "prost-types"
 version = "0.14.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f94967dc7688f3054c7fac87473ffae4cc4c3904800e2d9f5b857246d8963b0a"
 dependencies = [
- "prost",
+ "prost 0.14.4",
 ]
 
 [[package]]
@@ -7521,6 +7906,33 @@ version = "3.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95067976aca6421a523e491fce939a3e65249bac4b977adee0ee9771568e8aa3"
 
+[[package]]
+name = "protox"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f352af331bf637b8ecc720f7c87bf903d2571fa2e14a66e9b2558846864b54a"
+dependencies = [
+ "bytes",
+ "miette",
+ "prost 0.13.5",
+ "prost-reflect",
+ "prost-types 0.13.5",
+ "protox-parse",
+ "thiserror 1.0.69",
+]
+
+[[package]]
+name = "protox-parse"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3a462d115462c080ae000c29a47f0b3985737e5d3a995fcdbcaa5c782068dde"
+dependencies = [
+ "logos",
+ "miette",
+ "prost-types 0.13.5",
+ "thiserror 1.0.69",
+]
+
 [[package]]
 name = "pxfm"
 version = "0.1.30"
@@ -7559,7 +7971,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c1a41e437b6bbd489372cd4971de128e85c855f56c57f283d20ff016cf7c0a8"
 dependencies = [
  "bytes",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "pin-project-lite",
  "quinn-proto",
  "quinn-udp",
@@ -7601,7 +8013,7 @@ version = "0.5.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "35a133f956daabe89a61a685c2649f13d82d5aa4bd5d12d1277e1072a21c0694"
 dependencies = [
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "libc",
  "once_cell",
  "socket2",
@@ -7769,7 +8181,7 @@ dependencies = [
  "thiserror 2.0.18",
  "unicode-segmentation",
  "unicode-truncate",
- "unicode-width",
+ "unicode-width 0.2.2",
 ]
 
 [[package]]
@@ -7832,7 +8244,7 @@ dependencies = [
  "strum",
  "time",
  "unicode-segmentation",
- "unicode-width",
+ "unicode-width 0.2.2",
 ]
 
 [[package]]
@@ -7841,6 +8253,43 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "20675572f6f24e9e76ef639bc5552774ed45f1c30e2951e1e99c59888861c539"
 
+[[package]]
+name = "rawpointer"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60a357793950651c4ed0f3f52338f53b2f809f32d83a07f72909fa13e4c6c1e3"
+
+[[package]]
+name = "rayon"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb39b166781f92d482534ef4b4b1b2568f42613b53e5b6c160e24cfbfa30926d"
+dependencies = [
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-cond"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2964d0cf57a3e7a06e8183d14a8b527195c706b7983549cd5462d5aa3747438f"
+dependencies = [
+ "either",
+ "itertools",
+ "rayon",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22e18b0f0062d30d4230b2e85ff77fdfe4326feb054b9783a3460d8435c8ab91"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "realfft"
 version = "3.5.0"
@@ -8303,6 +8752,17 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "rustix-openpty"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1de16c7c59892b870a6336f185dc10943517f1327447096bbb7bb32cd85e2393"
+dependencies = [
+ "errno",
+ "libc",
+ "rustix 1.1.4",
+]
+
 [[package]]
 name = "rustls"
 version = "0.23.42"
@@ -8653,6 +9113,18 @@ version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd0b0ec5f1c1ca621c432a25813d8d60c88abe6d3e08a3eb9cf37d97a0fe3d73"
 
+[[package]]
+name = "sentencepiece-model"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40b87bf750a8322c3236d7aa63c1f4a6862187d00d2d8b038e1dfe263bfe43ec"
+dependencies = [
+ "miette",
+ "prost 0.13.5",
+ "prost-build 0.13.5",
+ "protox",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.228"
@@ -8836,6 +9308,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serial2"
+version = "0.2.38"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b16809bc35793b19ce4e0c53924bc0dce3937f15487997cfdaed936004180730"
+dependencies = [
+ "cfg-if 1.0.4",
+ "libc",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "serialize-to-javascript"
 version = "0.1.2"
@@ -8936,6 +9419,22 @@ dependencies = [
  "lazy_static",
 ]
 
+[[package]]
+name = "shared_library"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a9e7e0f2bfae24d8a5b5a66c5b257a83c7412304311512a0c054cd5e619da11"
+dependencies = [
+ "lazy_static",
+ "libc",
+]
+
+[[package]]
+name = "shell-words"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc6fe69c597f9c37bfeeeeeb33da3530379845f10be461a66d16d03eca2ded77"
+
 [[package]]
 name = "shellexpand"
 version = "3.1.2"
@@ -8985,6 +9484,16 @@ dependencies = [
  "signal-hook-registry",
 ]
 
+[[package]]
+name = "signal-hook"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2a0c28ca5908dbdbcd52e6fdaa00358ab88637f8ab33e1f188dd510eb44b53d"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
 [[package]]
 name = "signal-hook-mio"
 version = "0.2.5"
@@ -8993,7 +9502,7 @@ checksum = "b75a19a7a740b25bc7944bdee6172368f988763b744e3d4dfe753f6b4ece40cc"
 dependencies = [
  "libc",
  "mio",
- "signal-hook",
+ "signal-hook 0.3.18",
 ]
 
 [[package]]
@@ -9085,8 +9594,8 @@ name = "skippy-protocol"
 version = "0.74.0"
 source = "git+https://github.com/Mesh-LLM/mesh-llm.git?tag=v0.74.0#e60b2fe43aa05271569fbeff2a457133aef456a1"
 dependencies = [
- "prost",
- "prost-build",
+ "prost 0.14.4",
+ "prost-build 0.14.4",
  "protoc-bin-vendored",
  "serde",
 ]
@@ -9266,6 +9775,18 @@ dependencies = [
  "der",
 ]
 
+[[package]]
+name = "spm_precompiled"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5851699c4033c63636f7ea4cf7b7c1f1bf06d0cc03cfb42e711de5a5c46cf326"
+dependencies = [
+ "base64 0.13.1",
+ "nom 7.1.3",
+ "serde",
+ "unicode-segmentation",
+]
+
 [[package]]
 name = "sse-stream"
 version = "0.2.4"
@@ -9337,7 +9858,7 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a8f8038e7e7969abb3f1b7c2a811225e9296da208539e0f79c5251d6cac0025"
 dependencies = [
- "vte",
+ "vte 0.14.1",
 ]
 
 [[package]]
@@ -9400,6 +9921,7 @@ dependencies = [
  "symphonia-bundle-flac",
  "symphonia-bundle-mp3",
  "symphonia-codec-aac",
+ "symphonia-codec-alac",
  "symphonia-codec-pcm",
  "symphonia-codec-vorbis",
  "symphonia-core",
@@ -9444,6 +9966,16 @@ dependencies = [
  "symphonia-core",
 ]
 
+[[package]]
+name = "symphonia-codec-alac"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8413fa754942ac16a73634c9dfd1500ed5c61430956b33728567f667fdd393ab"
+dependencies = [
+ "log",
+ "symphonia-core",
+]
+
 [[package]]
 name = "symphonia-codec-pcm"
 version = "0.5.5"
@@ -9647,7 +10179,7 @@ version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fce91f2f0ec87dff7e6bcbbeb267439aa1188703003c6055193c821487400432"
 dependencies = [
- "unicode-width",
+ "unicode-width 0.2.2",
 ]
 
 [[package]]
@@ -10188,7 +10720,7 @@ dependencies = [
  "bitflags 2.13.0",
  "parking_lot",
  "rustix 1.1.4",
- "signal-hook",
+ "signal-hook 0.3.18",
  "windows-sys 0.61.2",
 ]
 
@@ -10222,7 +10754,7 @@ dependencies = [
  "anyhow",
  "base64 0.22.1",
  "bitflags 2.13.0",
- "fancy-regex",
+ "fancy-regex 0.11.0",
  "filedescriptor",
  "finl_unicode",
  "fixedbitset 0.4.2",
@@ -10239,7 +10771,7 @@ dependencies = [
  "pest_derive",
  "phf 0.11.3",
  "sha2 0.10.9",
- "signal-hook",
+ "signal-hook 0.3.18",
  "siphasher",
  "terminfo",
  "termios",
@@ -10385,6 +10917,39 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
+[[package]]
+name = "tokenizers"
+version = "0.22.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b238e22d44a15349529690fb07bd645cf58149a1b1e44d6cb5bd1641ff1a6223"
+dependencies = [
+ "ahash",
+ "aho-corasick",
+ "compact_str 0.9.1",
+ "dary_heap",
+ "derive_builder",
+ "esaxx-rs",
+ "fancy-regex 0.14.0",
+ "getrandom 0.3.4",
+ "itertools",
+ "log",
+ "macro_rules_attribute",
+ "monostate",
+ "paste",
+ "rand 0.9.4",
+ "rayon",
+ "rayon-cond",
+ "regex",
+ "regex-syntax",
+ "serde",
+ "serde_json",
+ "spm_precompiled",
+ "thiserror 2.0.18",
+ "unicode-normalization-alignments",
+ "unicode-segmentation",
+ "unicode_categories",
+]
+
 [[package]]
 name = "tokio"
 version = "1.52.3"
@@ -10718,7 +11283,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "50849f68853be452acf590cde0b146665b8d507b3b8af17261df47e02c209ea0"
 dependencies = [
  "bytes",
- "prost",
+ "prost 0.14.4",
  "tonic",
 ]
 
@@ -10899,7 +11464,7 @@ checksum = "b8765b90061cba6c22b5831f675da109ae5561588290f9fa2317adab2714d5a6"
 dependencies = [
  "memchr",
  "nom 8.0.0",
- "petgraph",
+ "petgraph 0.8.3",
 ]
 
 [[package]]
@@ -11070,6 +11635,15 @@ dependencies = [
  "tinyvec",
 ]
 
+[[package]]
+name = "unicode-normalization-alignments"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43f613e4fa046e69818dd287fdc4bc78175ff20331479dab6e1b0f98d57062de"
+dependencies = [
+ "smallvec",
+]
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.13.3"
@@ -11084,9 +11658,15 @@ checksum = "16b380a1238663e5f8a691f9039c73e1cdae598a30e9855f541d29b08b53e9a5"
 dependencies = [
  "itertools",
  "unicode-segmentation",
- "unicode-width",
+ "unicode-width 0.2.2",
 ]
 
+[[package]]
+name = "unicode-width"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7dd6e30e90baa6f72411720665d41d89b9a3d039dc45b8faea1ddd07f617f6af"
+
 [[package]]
 name = "unicode-width"
 version = "0.2.2"
@@ -11099,6 +11679,12 @@ version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
 
+[[package]]
+name = "unicode_categories"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39ec24b3121d976906ece63c9daad25b85969647682eee313cb5779fdd69e14e"
+
 [[package]]
 name = "universal-hash"
 version = "0.5.1"
@@ -11314,6 +11900,19 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "vte"
+version = "0.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5924018406ce0063cd67f8e008104968b74b563ee1b85dde3ed1f7cb87d3dbd"
+dependencies = [
+ "arrayvec",
+ "bitflags 2.13.0",
+ "cursor-icon",
+ "log",
+ "memchr",
+]
+
 [[package]]
 name = "vtparse"
 version = "0.6.2"
@@ -12384,6 +12983,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "winreg"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "80d0f4e272c85def139476380b12f9ac60926689dd2e01d4923222f40580869d"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "winreg"
 version = "0.55.0"
diff --git a/desktop/src-tauri/src/managed_agents/runtime.rs b/desktop/src-tauri/src/managed_agents/runtime.rs
index ec804869c4..e01acc62d9 100644
--- a/desktop/src-tauri/src/managed_agents/runtime.rs
+++ b/desktop/src-tauri/src/managed_agents/runtime.rs
@@ -911,11 +911,90 @@ pub fn spawn_agent_child(
     })
 }
 
+/// Log filter for the spawned harness and, through it, the agent.
+///
+/// `buzz-acp` inherits its stderr to the agent subprocess (`acp.rs:463`), so
+/// whatever this filter admits is what lands in the per-agent log file. That
+/// makes `buzz_agent` as load-bearing as `buzz_acp`: without it the agent's own
+/// turn diagnostics — compaction, the `_Stop` veto, max-rounds — are filtered
+/// out before they reach disk, and an agent misbehaving in the desktop leaves
+/// no trace to debug it with.
 fn child_rust_log_filter() -> String {
+    const DEFAULTS: &str = "buzz_acp=info,buzz_agent=info";
     match std::env::var("RUST_LOG") {
-        Ok(existing) if existing.contains("buzz_acp") => existing,
-        Ok(existing) if !existing.trim().is_empty() => format!("{existing},buzz_acp=info"),
-        _ => "buzz_acp=info".to_string(),
+        // An operator filter that already names both crates is taken verbatim.
+        Ok(existing) if existing.contains("buzz_acp") && existing.contains("buzz_agent") => {
+            existing
+        }
+        // Otherwise append only the directive that is missing, so an explicit
+        // `buzz_agent=debug` is not overridden by our default.
+        Ok(existing) if !existing.trim().is_empty() => {
+            let mut filter = existing;
+            if !filter.contains("buzz_acp") {
+                filter.push_str(",buzz_acp=info");
+            }
+            if !filter.contains("buzz_agent") {
+                filter.push_str(",buzz_agent=info");
+            }
+            filter
+        }
+        _ => DEFAULTS.to_string(),
+    }
+}
+
+#[cfg(test)]
+mod rust_log_filter_tests {
+    use super::child_rust_log_filter;
+
+    /// Serialize: `RUST_LOG` is process-global and these tests mutate it.
+    fn with_rust_log<T>(value: Option<&str>, body: impl FnOnce() -> T) -> T {
+        static LOCK: std::sync::Mutex<()> = std::sync::Mutex::new(());
+        let _guard = LOCK.lock().unwrap_or_else(|e| e.into_inner());
+        let previous = std::env::var("RUST_LOG").ok();
+        match value {
+            Some(v) => std::env::set_var("RUST_LOG", v),
+            None => std::env::remove_var("RUST_LOG"),
+        }
+        let result = body();
+        match previous {
+            Some(v) => std::env::set_var("RUST_LOG", v),
+            None => std::env::remove_var("RUST_LOG"),
+        }
+        result
+    }
+
+    #[test]
+    fn default_admits_both_the_harness_and_the_agent() {
+        // buzz_agent was missing here, which silently discarded every agent
+        // turn diagnostic from the desktop's per-agent log files.
+        let filter = with_rust_log(None, child_rust_log_filter);
+        assert!(filter.contains("buzz_acp=info"));
+        assert!(filter.contains("buzz_agent=info"));
+    }
+
+    #[test]
+    fn an_unrelated_operator_filter_is_extended_not_replaced() {
+        let filter = with_rust_log(Some("warn"), child_rust_log_filter);
+        assert!(filter.starts_with("warn"), "operator filter must survive");
+        assert!(filter.contains("buzz_acp=info"));
+        assert!(filter.contains("buzz_agent=info"));
+    }
+
+    #[test]
+    fn an_explicit_agent_directive_is_not_downgraded() {
+        let filter = with_rust_log(Some("buzz_agent=debug"), child_rust_log_filter);
+        assert!(filter.contains("buzz_agent=debug"));
+        assert!(!filter.contains("buzz_agent=info"), "must not override");
+        assert!(filter.contains("buzz_acp=info"), "still needs the harness");
+    }
+
+    #[test]
+    fn a_fully_specified_filter_is_taken_verbatim() {
+        let filter = with_rust_log(
+            Some("buzz_acp=warn,buzz_agent=trace"),
+            child_rust_log_filter,
+        );
+        assert_eq!(filter, "buzz_acp=warn,buzz_agent=trace");
     }
 }