Make ACP/Zed status obvious before users go source-diving

ROADMAP #21, #22, and #23 were already closed on current main, so the next real repo-local backlog item was the ACP/Zed discoverability gap. This adds a local `claw acp` status surface plus aliases, updates help/docs, and separates the shipped discoverability fix from the still-open daemon/protocol follow-up so editor-first users get a crisp answer immediately.

Constraint: No ACP/Zed daemon or protocol server exists in claw-code yet, so the new surface must be explicit status guidance rather than a fake implementation
Rejected: Add a pretend `acp serve` daemon path | would imply supported protocol behavior that does not exist
Rejected: Docs-only clarification | still leaves `claw --help` unable to answer the editor-launch question directly
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Keep ROADMAP discoverability fixes separate from future ACP daemon/protocol work so help text and backlog IDs stay unambiguous
Tested: cargo fmt --check; cargo clippy --workspace --all-targets -- -D warnings; cargo test --workspace; cargo run -q -p rusty-claude-cli -- acp; cargo run -q -p rusty-claude-cli -- --output-format json acp; architect review APPROVED
Not-tested: Real ACP/Zed daemon launch because no protocol-serving surface exists yet

rust/README.md

@@ -135,6 +135,7 @@ Top-level commands:
   version
   status
   sandbox
+  acp [serve]
   dump-manifests
   bootstrap-plan
   agents
@@ -144,6 +145,8 @@ Top-level commands:
   init
 ```
 
+`claw acp` is a local discoverability surface for editor-first users: it reports the current ACP/Zed status without starting the runtime. As of April 16, 2026, claw-code does **not** ship an ACP/Zed daemon entrypoint yet, and `claw acp serve` is only a status alias until the real protocol surface lands.
+
 The command surface is moving quickly. For the canonical live help text, run:
 
 ```bash