…inary consolidation

Add ACP custom method handlers for prompts, provider_info, plan_prompt,
and session/clear to close the gaps identified in issue block#7225. Add a
goose serve subcommand to start the ACP server over HTTP/WebSocket,
enabling binary consolidation (goose, goosed, goose-acp-server -> single binary).

New ACP methods:
- _goose/config/prompts: list extension prompts for a session
- _goose/config/prompt_info: get details for a single prompt by name
- _goose/agent/provider_info: get provider, model, context limit, tokens
- _goose/agent/plan_prompt: get the plan prompt string for a session
- _goose/session/clear: clear conversation and reset token counts

New CLI subcommand:
- goose serve [--host] [--port] [--with-builtin]: starts ACP server over HTTP/WS

Includes 7 integration tests covering all new methods and error cases.

Signed-off-by: fresh3nough <[email protected]>
Signed-off-by: fre <[email protected]>

Run generate-acp-schema + npm run generate to pick up the new custom
methods added in this PR. Also add transitional context comment on the
Serve subcommand linking to block#6642 and block#7697.

Signed-off-by: fre <[email protected]>

Fixes a race condition where session/clear could return success while a
streaming prompt task was still appending messages. Now cancels the
active CancellationToken and yields before resetting, ensuring the
prompt loop observes cancellation before the conversation is cleared.

Signed-off-by: fre <[email protected]>

Add optional 'extension' field to GetPromptInfoRequest so clients can
target a specific extension when multiple register the same prompt name.
When omitted, iterate extensions in sorted order for deterministic
results instead of relying on HashMap iteration order. Regenerated ACP
schema and TypeScript types.

Signed-off-by: fre <[email protected]>

… sessions

Replace yield_now() with an Arc<Notify> that the prompt task signals on
exit. session/clear now awaits this signal with an 800ms timeout before
resetting state, guaranteeing the streaming loop has stopped.

Also validate session existence via session_manager (SQLite) instead of
requiring an in-memory GooseAcpSession, so session/clear works on
persisted sessions consistent with session/get and session/delete.

Signed-off-by: fre <[email protected]>

Resolve conflict in crates/goose-acp/src/server.rs:
- Combine Notify (from branch) and OnceCell (from upstream) imports
- Keep branch's on_prompt setup which sets both cancel_token and prompt_done
- Keep all new custom methods added by this PR

Update crates/goose-acp/tests/new_custom_methods_test.rs to match
upstream API changes: use ClientToAgentConnection::expected_session_id()
and SessionResult destructuring instead of tuple unpacking.

Signed-off-by: fre <[email protected]>

Wrap agent.reply + stream loop in an async block so that
cancel_token/prompt_done are always cleared and done.notify_waiters()
is always called, even when an error causes an early return.
Previously, any ? propagation out of the stream loop (reply failure,
session-not-found, handle_message_content error, or explicit Err
return) left a stale prompt_done in the session, causing
session/clear to block for the full 800 ms timeout.

Signed-off-by: fresh3nough <[email protected]>
Signed-off-by: fre <[email protected]>