feat(relay): log WebSocket EVENT writes on the access target (#9154)

Logs every WebSocket `EVENT` on the access target
(`buzz_relay::access`). Before this, accepted writes logged only `Event
ingested` on the handler target, and refused or ephemeral writes logged
nothing.

### What's logged
Each `EVENT` frame writes one `event=write` line when its handler
finishes. The line has `conn_id`, `community`, `pubkey` (the
authenticated login, if any), `kind`, `event_id`, and
`outcome`/`reason`, taken from the OK the relay sent:
- `accepted`
- `rejected` (INFO), with `reason` set to the OK's NIP-01 prefix
(`invalid`, `restricted`, `auth-required`, `duplicate`, `rate-limited`,
…). Any other message is logged as `other`.
- `error` (WARN), when the OK starts with `error`
- `aborted`, when the handler ended before deciding an OK

`outcome` is always the relay's decision. If the OK couldn't be queued
because the outbound channel was full or closed, the line adds
`ok_queued=false`; the field is left off otherwise.

`EVENT`s refused before the handler runs are logged too, where their OK
is sent: admission rate limits, with admission's reason, and a full
handler pool, as `rate-limited`.

The OK text after the prefix, the event's content and its tag values are
never logged. Lines join to `auth`/`close` lines (and so to `peer_addr`)
through `conn_id`, the same way `req` lines do.

Rejected writes are capped per connection by the same refusal-budget
mechanism as refused reads, on their own counter: the first 16
rejections are logged and the rest are only counted, in a new
`writes_suppressed` field on the `close` line. Accepted writes are never
capped.

### How
`access::WriteLog` sends the OK and records it in one call
(`write.ok(...)`). That call replaces every
`conn.send(RelayMessage::ok(...))` in `handle_event` and the
observer-frame handler, so the line always shows what the client was
told.

### Tests
- `access::tests`: the reason comes from the OK prefix only; each
outcome logs at the right level and without content; rejected lines are
capped by the budget and accepted ones are not (draining the channel so
every OK is queued); an OK refused by a full or a closed outbound
channel keeps its outcome and adds `ok_queued=false`.
- `handlers::event::tests::fanout_access`: an unauthenticated `EVENT`
going through `handle_event` writes one `rejected`/`auth-required` line,
with no content or tag values.

---------

Signed-off-by: Will Pfleger <wpfleger@block.xyz>
Co-authored-by: Duncan <dcfd242e557282d7a1e2cf2e6877522682f1e5c6156dc92ca7d90eaedd3b0f95@buzz.block.builderlab.xyz>

desktop/src-tauri/Cargo.lock

@@ -1240,6 +1240,7 @@ dependencies = [
  "tracing",
  "ulid",
  "uuid",
+ "webp",
 ]
 
 [[package]]
@@ -2396,7 +2397,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccc2776f0c61eca1ca32528f85548abd1a4be8fb53d1b21c013e4f18da1e7090"
 dependencies = [
  "data-encoding",
- "syn 1.0.109",
+ "syn 2.0.118",
 ]
 
 [[package]]
@@ -4978,6 +4979,16 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "libwebp-sys"
+version = "0.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54cd30df7c7165ce74a456e4ca9732c603e8dc5e60784558c1c6dc047f876733"
+dependencies = [
+ "cc",
+ "glob",
+]
+
 [[package]]
 name = "line-clipping"
 version = "0.3.7"
@@ -11132,7 +11143,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32497e9a4c7b38532efcdebeef879707aa9f794296a4f0244f6f69e9bc8574bd"
 dependencies = [
  "fastrand",
- "getrandom 0.3.4",
+ "getrandom 0.4.3",
  "once_cell",
  "rustix",
  "windows-sys 0.61.2",
@@ -12632,6 +12643,15 @@ dependencies = [
  "system-deps",
 ]
 
+[[package]]
+name = "webp"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c071456adef4aca59bf6a583c46b90ff5eb0b4f758fc347cea81290288f37ce1"
+dependencies = [
+ "libwebp-sys",
+]
+
 [[package]]
 name = "webpki-root-certs"
 version = "1.0.10"