fix(acp): default subscribe=all excludes typing/presence (#3649)

[NanoRisk6]

What Problem This Solves

With BUZZ_ACP_SUBSCRIBE=all and no BUZZ_ACP_KINDS, the agent subscribed to every kind. Typing indicators (20002) and presence (20001) each started an agent turn — token burn per keystroke and a false Desktop “agent is typing” badge while the human typed. Fixes #3649.

Why This Change Was Made

Mentions mode already ships a curated default kinds list. All mode used kinds: None (NIP-01 wildcard).

Default for All (when kinds override is unset) is now a durable allowlist:

• stream messages (+ v2 / edits)
• deletions, reactions, gift-wrap DMs
• canvas, stream reminders
• workflow approval + trigger

Ephemeral kinds (typing, presence, observer frames) are not included.

BUZZ_ACP_KINDS=… still fully overrides (operators can re-add 20002 if they really want it).

Same default applied in resolve_dynamic_channel_filter for late-joined channels.

User Impact

Agents on subscribe=all respond to real channel work without paying a model call for every keystroke, and Desktop no longer shows the agent “typing” while the human composes.

Evidence

cargo test -p buzz-acp --lib test_all_mode
# test_all_mode_default_excludes_ephemeral_kinds ... ok
# test_all_mode_with_kinds_override ... ok
# test_all_mode_kinds_override_can_opt_into_typing ... ok