fix(kyberforge): resolve clean-context audit findings on primitive support

primitive-author:
- description excludes read-only review (-> factory-audit)
- validation Gotcha now matches the research: compile never reads
  prompts, install fails only on a bad Copilot hook payload and warns on
  prompt input names and dropped keys
- instruction fold-in into AGENTS.md/CLAUDE.md stated as conditional on
  dedup and --force-instructions
- hook checklist gains the wrapped-shape Must, drops hardlinks, notes
  why executable is stricter than the research, and states the
  separate Copilot-targeted package route instead of a blanket "don't"
- prompt Must 5 keeps the research's Copilot-only-key exception; adds
  model-slug and 250-char Shoulds; descriptions name skills or agents
- placeholder instruction covers both FILL IN and FILL_IN_ tokens

factory-audit: hardlink FAIL scoped to instructions and prompts
(find_hook_files skips symlinks only), with bats cases; prompt-flow
description rubric names skills or agents.

forge: version-bump, apm-routes and sources references updated for the
primitive route.

Refs #94

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KkT7RSDwDbmrM9T34b6sTi

plugins/kyberforge/.apm/skills/primitive-author/references/prompt.md

@@ -23,15 +23,16 @@ worse skill on every harness.
   afterwards, come back and write it against the new skill.
 - **A single-intent message the user would otherwise type repeatedly, steering existing skills or
   agents by name** → continue. Confirm each skill or agent it names exists and is not
-  `disable-model-invocation: true`, which the model cannot invoke.
+  `disable-model-invocation: true`: the prompt's body reaches the model, and the model cannot
+  invoke a skill that sets it, so the steering would dead-end (the same check `factory-audit`'s
+  prompt flow applies).
 
 ## Description contract
 
-One plain, user-facing sentence stating the action and naming the skills it steers — "Review the
+One plain, user-facing sentence stating the action and naming the skills or agents it steers — "Review the
 current PR with `gitea-prs` and `factory-audit`, then summarise the findings." No "Use when"
 trigger clause and no `Not X -> Y` boundary: on Claude the description is model-visible, and a
-trigger clause invites the router to pick the wrapper over the skills it wraps. 250 characters at
-most.
+trigger clause invites the router to pick the wrapper over the skills it wraps.
 
 ## Checklist
 
@@ -50,10 +51,14 @@ Must:
 4. Every `${input:x}` in the body is declared in `input:`, and every declared name is used. Without
    `input:`, no `${input:…}` may appear — it would reach Claude unrewritten.
 5. Frontmatter keys stay within `description`, `allowed-tools`, `model`, `argument-hint` and
-   `input`. Claude drops everything else with only a warning.
+   `input`. Claude drops everything else with only a warning. The one exception: a Copilot-only key
+   (`agent`, `tools`, …) that is intended, with its Claude drop accepted and said so.
 
 Should:
 
 6. Spell keys in kebab-case — `allowed-tools`, `argument-hint` — not the camelCase aliases.
 7. Omit `argument-hint` when `input:` is set; apm synthesises `<a> <b>` from the input names.
 8. Keep one intent per prompt, and write the body as second-person instructions.
+9. Keep `description` to 250 characters or fewer.
+10. Give `model` a slug the target accepts. Copilot ignores `allowed-tools` and `model`, so neither
+    constrains a Copilot run.