feat: restore ACP server implementation from PR #949 (#1254)

Restore the ACP editor-integration implementation that was present on the
original PR branch but did not actually land in main.

Includes:
- acp_adapter/ server, session manager, event bridge, auth, permissions,
  and tool helpers
- hermes acp subcommand and hermes-acp entry point
- hermes-acp curated toolset
- ACP registry manifest, setup guide, and ACP test suite
- jupyter-live-kernel data science skill from the original branch

Also updates the revived ACP code for current main by:
- resolving runtime providers through the modern shared provider router
- binding ACP sessions to per-session cwd task overrides
- tracking duplicate same-name tool calls with FIFO IDs
- restoring terminal approval callbacks after prompts
- normalizing supporting docs/skill metadata

Validated with tests/acp and the full pytest suite (-n0).

acp_adapter/auth.py

@@ -0,0 +1,24 @@
+"""ACP auth helpers — detect the currently configured Hermes provider."""
+
+from __future__ import annotations
+
+from typing import Optional
+
+
+def detect_provider() -> Optional[str]:
+    """Resolve the active Hermes runtime provider, or None if unavailable."""
+    try:
+        from hermes_cli.runtime_provider import resolve_runtime_provider
+        runtime = resolve_runtime_provider()
+        api_key = runtime.get("api_key")
+        provider = runtime.get("provider")
+        if isinstance(api_key, str) and api_key.strip() and isinstance(provider, str) and provider.strip():
+            return provider.strip().lower()
+    except Exception:
+        return None
+    return None
+
+
+def has_provider() -> bool:
+    """Return True if Hermes can resolve any runtime provider credentials."""
+    return detect_provider() is not None