## Why
Thread-scoped ACP sessions from #6732 need an opt-in desktop rollout
that preserves today’s channel policy by default.
## What
- Add the default-off “Thread Scoped ACP Sessions” toggle under Settings
→ Experiments using the existing feature-override persistence.
- Map the persisted setting to `BUZZ_ACP_SESSION_POLICY=channel|thread`
for every local and provider-backed managed ACP launch. Changes apply
when managed agents next start; DMs remain conversation-scoped by the
backend.
- Keep the desktop setting authoritative over descriptor environment and
cover the UI, persistence, local spawn, provider payload, and existing
Projects/Workflows experiments.
## Risk Assessment
Low. The experiment defaults off and explicitly preserves `channel`;
changes are limited to managed-agent launch configuration. Existing
running agents are unchanged until their next start.
## Testing
- `. ./bin/activate-hermit && just ci` — passed on the final restacked
tree, including 5,674 desktop tests, 2,796 Tauri tests, and 1,860 mobile
tests.
- `cd desktop && pnpm build:e2e && pnpm exec playwright test
tests/e2e/experimental-features.spec.ts --project=smoke` — 1 passed.
- `. ./bin/activate-hermit && cargo test --manifest-path
desktop/src-tauri/Cargo.toml session_policy --lib` — 4 passed.
- `. ./bin/activate-hermit && cargo test --manifest-path
desktop/src-tauri/Cargo.toml commands::agents::deploy::tests --lib` — 15
passed.
- `. ./bin/activate-hermit && cargo test -p buzz-backend-kubernetes
--test wire_fixtures` — 4 passed.
## Stack Info
Stacked on #6732. This PR depends on #6732 and should merge after it.
Generated with Codex
---------
Signed-off-by: Salman Mohammed <smohammed@squareup.com>
Signed-off-by: Leo <5faf251baee50ee6bcde338aef6acdd70bb3e60115664c2cd490d94a55dfc488@buzz.block.builderlab.xyz>
Co-authored-by: Leo <5faf251baee50ee6bcde338aef6acdd70bb3e60115664c2cd490d94a55dfc488@buzz.block.builderlab.xyz>
Relands **#2467** (extract `buzz-voice` crate) and **#3208** (Pocket
voice settings) onto main, after #3266 and #3180 merged.
## Why a fresh PR
The repo is squash-only with delete-branch-on-merge. Squashing #3266
deleted `jtennant/pocket-tts-2026-04`, which was #2467's base — GitHub
auto-closed #2467 and it cannot be reopened. Squash merges also sever
ancestry, so GitHub's natural merge-base reports phantom conflicts for
the whole remaining stack.
## Content provenance
- Byte-identical to the blessed `jt/buzz-voice-refactor` branch
(`93029c577`, tree `6729e0eff` — reviewed by Dawn (#2467) and Max
(#3208) at exact heads) **except** the three files where #3180 and #3208
genuinely interact.
- Three-file resolution (union of both sides):
- `huddle/mod.rs` — #3180's pipeline re-exports + #3208's
`agent_tts_routing` imports.
- `huddle/state.rs` — `reset_preserving_generation` preserves both
`huddle_generation` (#3180) and `tts_enabled` (#3208); test sets merged
into one `tests` module.
- `desktop/src/testing/e2eBridge.ts` — both switch arms kept; no
duplicate case labels.
## Verification at cf32dacd7
- `cargo test` (desktop/src-tauri, pinned 1.95.0): **2047 + 3 pass / 0
fail** (14 ignored: 8 keychain, 4 real_relay, 2 flag-gated)
- `cargo clippy --all-targets -- -D warnings`: clean; `cargo fmt
--check`: clean
- `cargo check --workspace` (root, includes new `buzz-voice` member):
clean; `cargo test -p buzz-voice`: 5/0
- `pnpm test`: **3885 / 0**; `tsc --noEmit`: clean; lint: clean
The 3180×3208 interaction resolution is getting an independent team
re-review before merge.
Buzz channel: buzz-desktop-voice `fd5fb402-b651-4238-89b1-bb3e2fa4dc96`,
thread `b4798ecc`.
Signed-off-by: npub1qyvc0c5kl4gqv2fd97fsk46tu378sqgy35vc83rvgfwne90sel7s0ed67d <011987e296fd5006292d2f930b574be47c7801048d1983c46c425d3c95f0cffd@buzz.block.builderlab.xyz>
Co-authored-by: npub1qyvc0c5kl4gqv2fd97fsk46tu378sqgy35vc83rvgfwne90sel7s0ed67d <011987e296fd5006292d2f930b574be47c7801048d1983c46c425d3c95f0cffd@buzz.block.builderlab.xyz>
