docs: stop the preloaded instruction set asserting machine state

Why: four defects in the files every session pays for, all introduced or left
behind by the trim.

AGENTS.md told agents the `<plugin>:` form still resolves "because user-scope
native installs were left enabled on purpose", and that a working namespaced
call "is not something to fix". That premise is false on this machine:
installed_plugins.json is empty, no enabledPlugins key exists in ~/.claude.json,
and ~/.apm/marketplaces.json is empty. ADR-0018 already reversed itself once on
this exact claim (Correction 2026-08-14) using that same enablement as its
evidence, so flipping the assertion again would be the third revision in three.
Both files now assert nothing about install state at all, which removes the
flip-flop surface instead of re-aiming it.

The other three are guard-rails whose instruction survived the trim while the
caveat that made it safe did not:
- The run-tests.sh line omitted --strict, so it named the one invocation that
  reports SKIPPED rather than failed when a dependency is missing. gates.md
  records this gate going green having verified 15 of 17 suites on a vale-less
  PATH. .pre-commit-config.yaml:70 already uses --strict for that reason.
- The .claude/settings.json prohibition lost its ADR-0019 exception, so an agent
  applying it literally would strip apm's own merged SessionStart entry and
  create the drift the rule exists to prevent.
- LESSONS.md still routed graduated rules to CONTEXT.md's Principles section,
  which this branch deleted.

Implementation notes: the six terms the trim dropped while AGENTS.md still
claimed CONTEXT.md glosses everything -- authoring root, content mirror, apm
package, output profile, near-miss, vacuous green -- are restored as one-line
entries per CONTEXT-FORMAT.md, sourced from architecture.md, gates.md and
skill-audit's description-quality.md rather than reworded. ADR-0018 gets a third
dated note recording the observation and the fact that the state has now been
described two ways, and its stale user-scope inventory is replaced by a pointer
to it; the decision it records is untouched. LESSONS.md:3 carried the identical
stale claim as :5 and is fixed with it.

Impact: preloaded context is now free of assertions about machine state.

Refs: #105

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TmFqzpuExLJv3m114XVE9w

AGENTS.md

@@ -27,17 +27,17 @@ This repo dogfoods its own plugins. Before shelling out, check whether a skill a
 - Vale prose linting → `vale-config` / `vale-run`
 - This repo's own AGENTS.md → `agentsmd-author` / `agentsmd-audit`
 
-Use the bare, **unnamespaced** names. The `<plugin>:` form (`gitea:gitea-prs`) also still resolves, because user-scope native installs were left enabled on purpose (ADR-0018) — a working namespaced call is not evidence that anything is broken and is not something to "fix". Prefer the bare name anyway: it is what `apm install` deploys, and what survives those user-scope installs eventually being converted.
+Use the bare, **unnamespaced** names. That is what `apm install` deploys and the only form this repo's own install produces — a project skill has no plugin to prefix (ADR-0018). Whether the `<plugin>:` form (`gitea:gitea-prs`) also resolves depends on native plugin installs at user scope, outside this repo; write the bare name either way.
 
 Fall back to raw shell only when no skill covers it.
 
 ## Session rules
 
-- **Do not add repo-owned keys to `.claude/settings.json`.** apm treats it as its own deployed artifact and `apm audit --ci` replays the install and diffs, so anything apm would not have written is permanent drift that fails the `apm-audit-ci` pre-push hook. A hook you want here is authored in `plugins/<name>/.apm/hooks/` and deployed by apm, never hand-written into that file. Machine-specific settings go in the gitignored `.claude/settings.local.json`; shared enforcement goes in `.pre-commit-config.yaml`.
+- **Do not add repo-owned keys to `.claude/settings.json`.** apm treats it as its own deployed artifact and `apm audit --ci` replays the install and diffs, so anything apm would not have written is permanent drift that fails the `apm-audit-ci` pre-push hook. A hook you want here is authored in `plugins/<name>/.apm/hooks/` and deployed by apm, never hand-written into that file. The `SessionStart` entry already in it is exactly that: kyberforge authors it in `plugins/kyberforge/.apm/hooks/hooks.json` and apm merges it in, so it is apm's own output, it is what the replay expects, and it belongs in the commit — do not strip it (ADR-0019). Machine-specific settings go in the gitignored `.claude/settings.local.json`; shared enforcement goes in `.pre-commit-config.yaml`.
 - **`apm.lock.yaml` turning up modified is expected, not a bug.** kyberforge's `SessionStart` hook runs `apm outdated` at startup and `apm update --yes` when something is behind, which rewrites the lock. Commit or discard it deliberately.
 - **A `.apm/` edit is not live in this session until it is pushed.** The six dependencies resolve from the holocron remote, unpinned against the default branch. `apm install` deploys from the lock; `apm update` is what re-resolves refs.
 - **The ADR-0020 skill gates ship hot, with no baseline.** 26 of 39 descriptions and 9 of 39 bodies exceed their FAIL tier, and the `Kyberforge.CompositionNote` Vale rule fires 10 errors across `gitea-issues`, `gitea-labels-milestones`, `gitea-prs` and `gitea-workflow`. Editing any of those skills *for any reason* means retrofitting it to the contract first — a one-line fix cannot be committed until the skill complies. Deliberate; tracked as Gitea issue #99. `skill-size-check` will not warn you about the Vale half, so check both: `pre-commit run --all-files`.
-- **Run `bash tests/run-tests.sh` before considering any change done.**
+- **Run `bash tests/run-tests.sh --strict` before considering any change done.** Keep the flag: without it a suite whose dependency is missing exits 77 and is counted SKIPPED rather than failed, so the run goes green having verified less than it claims.
 - **Before pushing, run the whole gate locally:** `pre-commit run --hook-stage pre-push --all-files`. Pushing runs 14 repo-defined hooks, not just the test suite.
 - **Pushing without a network** needs `SKIP=apm-marketplace-check,apm-pack-check-clean git push` — those two resolve a remote marketplace entry via `git ls-remote`. Skip only those two; the rest are real local checks, and adding one to `SKIP` disarms it silently.
 - **Author commits with `git-commits`** — it validates Conventional Commits, which `commit-msg` enforces.