feat(moments): skills and stored processes declare the moments they are for (milestone 458 step 5, #4923)

Loading a procedure now also reaches the moment it is for. Loading the
reporting procedure is a report; loading the release procedure is a delivery.

- Bundled skills: each SKILL.md declares `metadata: moments:`. The same
  declaration ships as Skill defaults (BUNDLED_SKILL_MOMENTS), because the
  server never sees the plugin's files. test_skill_moments holds the two
  together and pins the plugin name that qualifies the skill.
- Stored processes: `moments` on create_process and update_process, stored
  in the note's data and returned by get_process. A `scribe-proc-<slug>`
  load resolves its process through the sync manifest at load time. The
  moments are not copied into the stub, which would go stale mid-session.
- reachable_tools lists the skill loader whenever anything is mounted, since
  a process's moments are known only when it loads.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_skill_moments.py

@@ -0,0 +1,84 @@
+"""The bundled skills declare the moments they are for (milestone 458 step 5).
+
+Loading the reporting procedure is a report; loading the planning procedure
+is planning. Each SKILL.md says which moment it is for in its frontmatter
+(`metadata: moments:`), where an author editing the skill sees it — but the
+server that resolves a skill load to its moments never sees the plugin's
+files, so the same declaration ships as defaults in
+`moment_actions.BUNDLED_SKILL_MOMENTS`. Two copies drift unless something
+holds them together; this does, in both directions, and every skill has to
+make the choice rather than inherit silence.
+"""
+from __future__ import annotations
+
+import json
+import re
+from pathlib import Path
+
+from scribe.services import moment_actions as ma
+from scribe.services import moments
+
+ROOT = Path(__file__).resolve().parents[1]
+SKILLS = ROOT / "plugin" / "skills"
+MANIFEST = ROOT / "plugin" / ".claude-plugin" / "plugin.json"
+
+_FRONT = re.compile(r"\A---\n(.*?)\n---\n", re.S)
+_METADATA = re.compile(r"^metadata:[ \t]*\n((?:[ \t]+\S.*(?:\n|\Z))*)", re.M)
+_MOMENTS = re.compile(r"^[ \t]+moments:[ \t]*(.*)$", re.M)
+
+
+def declared(text: str) -> tuple[str, ...]:
+    """The moments a SKILL.md's frontmatter declares; () when it declares none.
+
+    Agent Skills metadata maps strings to strings, so several moments are one
+    comma-separated value.
+    """
+    front = _FRONT.match(text)
+    meta = _METADATA.search(front.group(1)) if front else None
+    line = _MOMENTS.search(meta.group(1)) if meta else None
+    if not line:
+        return ()
+    return tuple(m.strip() for m in line.group(1).split(",") if m.strip())
+
+
+def _on_disk() -> dict[str, tuple[str, ...]]:
+    return {p.parent.name: declared(p.read_text()) for p in sorted(SKILLS.glob("*/SKILL.md"))}
+
+
+def test_the_reader_finds_a_declaration_and_only_in_the_frontmatter():
+    """The guard below is only as good as this reader, so it must be able to
+    say no: a declaration in the body, or none at all, reads as nothing."""
+    assert declared(
+        "---\nname: x\ndescription: y\nmetadata:\n  moments: work.plan, reply.report\n---\nbody\n"
+    ) == ("work.plan", "reply.report")
+    assert declared("---\nname: x\ndescription: y\n---\nmetadata:\n  moments: work.plan\n") == ()
+    assert declared("---\nname: x\nmetadata:\n  author: someone\n---\n") == ()
+    assert declared("no frontmatter\n") == ()
+
+
+def test_every_bundled_skill_declares_the_moments_it_is_for():
+    silent = [name for name, found in _on_disk().items() if not found]
+    assert not silent, (
+        f"{silent} declare no moment. Add `metadata:` / `  moments: <moment>` to "
+        f"the frontmatter (list_moments has the catalog) and the same entry to "
+        f"moment_actions.BUNDLED_SKILL_MOMENTS"
+    )
+
+
+def test_the_frontmatter_and_the_shipped_defaults_agree():
+    assert _on_disk() == ma.BUNDLED_SKILL_MOMENTS, (
+        "a SKILL.md's `metadata: moments:` and moment_actions.BUNDLED_SKILL_MOMENTS "
+        "disagree — the server reads only the latter, so change both together"
+    )
+
+
+def test_every_declared_moment_is_in_the_catalog():
+    bad = {name: found for name, found in _on_disk().items()
+           if any(m not in moments.MOMENTS for m in found)}
+    assert not bad, bad
+
+
+def test_the_defaults_qualify_skills_by_the_plugins_own_name():
+    """The harness names a plugin's skill `<plugin>:<skill>`, so the defaults
+    match only while this agrees with the manifest."""
+    assert json.loads(MANIFEST.read_text())["name"] == ma.BUNDLED_SKILL_PLUGIN