feat: task_completed signal — post-task skill capture (v0.3.2)

Adds an 11th signal type emitted when a run of work (between two
UserPromptSubmit events) crosses three quality gates:
  - >=5 tool calls (TASK_TOOL_MIN)
  - >=3 distinct tool kinds (TASK_DIVERSITY_MIN, filters single-tool
    sweeps like "wrote 5 files")
  - 0 correction signals during the run (filters tasks where the user
    pushed back; correction-during-task disqualifies the recipe)

Payload carries tool_count, tool_kinds, active_skills, active_agents
so the agent can cluster by sorted tool-kind tuple and route through
the existing skill-overlap rule (skill_new vs skill_edit).

Importantly: cross_session_evidence is FALSE on first occurrence,
so resulting skill_new proposals always queue for review — they only
auto-apply when the same multi-tool recipe recurs in a second session
(then the existing rubric kicks in). Post-task creation captures novel
patterns while preserving the rule "auto-apply requires cross-session".

Hook adds state fields: task_tool_count, task_tool_kinds, task_corrections.
All reset on UserPromptSubmit boundary and on session change.

Agent gets one new signal-types-table row and one clustering bullet
referencing the existing skill-overlap rule.

3 new tests (30 passed, 0 failed):
  - 5 tools + 5 kinds + 0 corrections fires task_completed
  - 5 tools + 1 kind (Edit only) does NOT fire (diversity gate)
  - 5 tools + 3 kinds + correction-on-closing-prompt does NOT fire

agents/adam.md

@@ -38,6 +38,7 @@ The hook emits these `type` values into the journal:
 | `subagent_dispatch_pattern` | same subagent dispatched ≥3× cumulatively | subagent_type |
 | `correction_free_streak` | 5 clean UserPromptSubmits in a row (no correction phrase) | `active_skills[0]` |
 | `clean_recovery` | 3 clean PostToolUse events after a `tool_error_loop`/`dead_end`/`retry_loop` | (`recovered_from`, `active_skills[0]`) |
+| `task_completed` | UserPromptSubmit closes a run of ≥5 tool calls with ≥3 distinct tool kinds and 0 corrections | sorted `tool_kinds` tuple |
 
 ## Process
 
@@ -62,6 +63,7 @@ The hook emits these `type` values into the journal:
    - `subagent_dispatch_pattern`: cluster by `subagent_type`.
    - `correction_free_streak`: cluster by `active_skills[0]`. Treat ≥3 streaks across ≥2 sessions naming the same skill as cross-session evidence.
    - `clean_recovery`: cluster by (`recovered_from`, `active_skills[0]`). A win cluster qualifies for `skill_edit` only when the named skill exists in `skills_root`.
+   - `task_completed`: cluster by sorted `tool_kinds` tuple (the multi-tool recipe). Single entry qualifies for `skill_new` proposal (drafting protocol applies). Cross-session evidence requires ≥2 entries from distinct sessions with same tuple — without it, proposal queues, never auto-applies. Run the existing skill-overlap rule before drafting: if the recipe matches an existing skill's name/description tokens, route to `skill_edit` instead.
 5. **Multi-axis correlation**: for each session that produced ≥2 distinct struggle types (`tool_error_loop`, `dead_end`, `weak_agent`, `retry_loop`, `edit_churn`, `build_loop`), tag clusters from that session as `multi_axis: true`. This grants +1 confidence at scoring.
 6. For each cluster qualifying under the rubric — ≥3 occurrences across ≥2 sessions, OR (for struggle types) ≥1 entry within a single session, OR (for `correction`) ≥3 occurrences across ≥2 cwds:
    a. If cluster topic matches a rejected idea via the rejected-ideas fuzzy set (≥2 token overlap with rejection's `# Why`), skip with reason `"rejected-similar"`.