refactor: drop dev-cycle-profile.yml for conventions + CLAUDE.md facts

The profile was never parsed — it was prose the skill bodies told the model to read, so most slots were dead, constant across every project, or fiction (the whole pipeline block, including the "tdd is opt-in" claim, was enforced by nothing).

Split it in two: constants become fixed conventions named directly by the skills (new docs/conventions.md), and the few genuinely per-project facts move to each project's CLAUDE.md under '## Skills plugin: project facts'. tdd/fieldtest/docwriter are now always available; the only behavioural toggle left is spec auto-sign.

Delete docs/profile-schema.md and templates/project-profile.yml; add docs/conventions.md and a project-facts section to templates/CLAUDE.md.fragment; rewrite all SKILL/agent prose and the pipeline/design/migration/README/INSTALL docs accordingly.

audit/agents/bencher.md

@@ -34,8 +34,9 @@ over it with a chart.
 
 ## Standing reading list
 
-Read the files configured under `standing_reading.always` plus
-`standing_reading.by_role.bencher` in the project profile.
+Always read `CLAUDE.md` and `git log -10 --format=full`, plus
+the per-role standing reading the project lists in its
+CLAUDE.md project facts for the bencher role.
 
 For diagnostics on a specific regression script, read the
 script itself and any prior result baselines it references