fix(acp): dispatch mentioned forum events

[Jross1719]

Summary

• include forum posts (45001) and forum comments (45003) in the ACP harness's default mention subscriptions
• keep mention gating enabled and continue excluding forum votes (45002)
• share the default kind list across static, dynamic, and main-loop subscription paths
• preserve setup mode's intentionally narrower defaults and update the forum documentation

Root cause

The ACP harness subscribed to stream messages, workflow requests, and reminders by default, but omitted forum post and comment kinds. The relay's existing p-tag filter is kind-agnostic, so explicitly mentioned agents were never reached because those forum event kinds were not subscribed.

Impact

Agents now wake for forum posts and comments that explicitly mention them. Unmentioned forum traffic and forum votes remain excluded unless an operator opts into broader kinds and disables mention filtering.

Validation

• cargo test -p buzz-acp --lib — 777 passed
• cargo test -p buzz-acp --test '*' — 9 passed
• cargo test -p buzz-sdk --lib — 257 passed
• cargo test --doc -p buzz-acp — passed
• cargo fmt --check -p buzz-acp — passed
• cargo clippy --workspace --all-targets -- -D warnings — passed
• git diff --check — passed

[Jross1719]

@block/buzz-oss-team Review requested for this focused ACP dispatch fix. It adds explicitly mentioned forum posts/comments (45001/45003) to the default mention-only paths, keeps votes (45002) excluded, and preserves the p-tag gate in both normal and setup modes.

Local verification on head 88ed71094bfae97cc3c0d4546801fedc97246bc0: 777 library tests and 9 integration tests passed; cargo fmt --check, strict package Clippy, git diff --check, and DCO are clean.

[themiguelamador]

The forum-kind addition is sound, but the consolidated defaults expose a related message-coverage regression: both normal and setup mention lists omit KIND_STREAM_MESSAGE_V2 (40002). Buzz treats kinds 9 and 40002 as canonical channel messages throughout its message, feed, and mention paths. As written, an ACP agent still never receives a direct mention carried by a v2 stream event, and an unconfigured agent cannot publish its setup nudge for one.

The README's replacement --kinds and TOML examples also omit 40002. Because --kinds replaces the default wholesale, following the documented “all forum activity” setup preserves that same coverage hole.

I fixed the normal/setup defaults, regression assertions, and all documented override lists in 25d100ae1 (review/pr-5936-fix).

Verification completed on the fix commit:

• cargo test -p buzz-acp --lib — 777 passed
• cargo test -p buzz-acp --test '*' — 9 passed
• cargo test --doc -p buzz-acp — passed
• cargo clippy -p buzz-acp --all-targets -- -D warnings
• cargo fmt --all -- --check
• git diff --check

Please incorporate the fix commit (or an equivalent change) before merge.