🤖 Apply lean Athanor review fixes

Adept dispatches no longer pass a model alias over the pin. Igor checks
the stamped model id of plan, attack and phase-review outputs before
acting on them. Implementation work no longer goes to the Athanor as an
unplanned brief. The spawning reference says plainly that "verified"
means read from the schema, marks fork availability unverified, and
cites the 184/184 evidence for alias-over-pin. Minor consistency fixes:
trunk notes, re-check failure path, staging, fallout diffs, run-log
timing.

plugins/spire/skills/igor/references/model-tiers.md

@@ -16,7 +16,7 @@ Prefer a project-pinned agent from `.claude/agents/` when one matches the task;
 Rules of thumb:
 
 - One task -> one subagent with an explicit output file path in the workpad.
-- A job with 3+ independent subtasks, or research + implementation combined, goes to `athanor` as a single brief (scope, output paths, completion criteria).
+- Implementation goes through the cycle (plan → attack the plan → build): the `athanor` gets a reshaped build plan, never an unplanned build brief. A non-build job with 3+ independent subtasks (research cascade, audit) may go to `athanor` as a single brief (scope, output paths, completion criteria).
 - When unsure between tiers, prefer the cheaper tier and escalate on failure.
 
 Write-capability guard: