feat(self-check): harness smoke tests lock in the 1.4.0 invariants (VERSION 1.4.1)

Adds a 'harness' category to /self-check (Task 12, self-check half) so the harness-
optimization gains can't silently regress. All read-only / non-invasive:
- VERSION marker present + not older than manifest.harness.min_version
- skill-registry description budget (sum of all SKILL.md description: fields under
  registry_desc_budget_chars) -- the metric that catches Task 5 bloating back
- global deploy targets ~/.claude/skills + ~/.claude/commands populated (Mac-wipe failure)
- harness-guard.sh present + wired into sync.sh
- core scripts parse (bash -n on sync/guard/now-phoenix); now-phoenix.sh emits a valid date

Tunables in baseline/manifest.json 'harness' block. Verified 9/9 PASS; budget WARN
negative-tested at a synthetic over-budget value.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/skills/self-check/baseline/manifest.json

@@ -5,6 +5,19 @@
   "derived_at": "2026-06-02",
   "note": "PROVISIONAL baseline, generated from a single known-good machine. V1 of self-check is a CENSUS tool: every machine probes itself, publishes to the coord API, and we refine this manifest from real fleet data (see baseline/README.md). Do NOT treat 'extra' or 'missing' items as authoritative until the fleet census has confirmed them across machines.",
 
+  "harness": {
+    "min_version": "1.4.0",
+    "version_file": ".claude/harness/VERSION",
+    "registry_desc_budget_chars": 10500,
+    "registry_desc_why": "Sum of all skill SKILL.md description: fields. These inject into EVERY session's skill registry, so a bloated description is a fleet-wide context tax. Budget set at the 1.4.0 post-trim size (~8.7k) + headroom; a WARN here means a skill description grew back and should be re-trimmed (move triggers/examples into the SKILL.md body).",
+    "syntax_check_scripts": [
+      ".claude/scripts/sync.sh",
+      ".claude/scripts/harness-guard.sh",
+      ".claude/scripts/now-phoenix.sh"
+    ],
+    "guard_wired_in": ".claude/scripts/sync.sh"
+  },
+
   "required_tools": [
     { "name": "bash",   "why": "hooks, scripts, sync, vault wrapper" },
     { "name": "git",    "why": "repo + submodules + Gitea sync" },