docs: CLAUDE.md becomes a core plus path-scoped rules (R-229)

215 lines -> 110 (92 effective; block-level HTML comments are stripped before
injection and never reach the model, verified empirically on Claude Code 2.1.222
with a control and a treatment run).

Four new .claude/rules/*.md, each with a paths: glob list so it loads only when a
matching file is read: gates, ui-hungarian, backup-paths, agent-coupling.

The ## Layout tree was deleted as derivable; REUSE.md already owns the per-package
seams its annotations stood in for. The host/access table was deleted in favour of
a pointer to documentation/operations/nodes.md -- it carried three defects at once:
demo-felhom given as the LAN fallback address as if it were the route, a pinned
"agent 0.93.0" against the project's own no-versions-in-docs rule, and the claim
that no drill VM was provisioned on demo-hp. Measured live: qm list shows VM 300
drill-r50. felhom-agent/CLAUDE.md was right; this file was wrong.

Kept verbatim: the seven session-critical invariants, the F9 live-validation fence,
the end-of-session checklist.

controller_gates.py registers the shared instructions gate (felhom.eu/scripts/,
never copied here; an absent sibling clone FAILS).

Docs only -- no Go, no version bump, no image, no deploy.
Ledger: felhom.eu/documentation/audits/LEDGER-instruction-trim-2026-08-06.md

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JJc8sAGRWmavP3rMtdpkr2

controller/scripts/controller_gates.py

@@ -45,6 +45,8 @@ SCRIPTS = os.path.dirname(os.path.abspath(__file__))
 CTRL = os.path.dirname(SCRIPTS)                 # <repo>/controller — every gate's cwd
 REPO = os.path.dirname(CTRL)                    # <repo> — the root REUSE.md lives here
 SHARED_REUSE = os.path.join(os.path.dirname(REPO), "felhom.eu", "scripts", "reuse_refs_check.py")
+SHARED_INSTRUCTIONS = os.path.join(
+    os.path.dirname(REPO), "felhom.eu", "scripts", "instructions_gate.py")
 
 # (label, absolute script path, args, fast)
 GATES = [
@@ -56,6 +58,7 @@ GATES = [
     ("mojibake",       os.path.join(SCRIPTS, "mojibake_gate.py"),               [],       True),
     ("docker-v",       os.path.join(SCRIPTS, "docker_run_volume_path_gate.py"), [],       True),
     ("reuse-refs",     SHARED_REUSE,                                            [REPO],   True),
+    ("instructions",   SHARED_INSTRUCTIONS,                                     [REPO],   True),
 ]
 
 VERDICT = {0: "OK", 1: "FAILED", 2: "INCONCLUSIVE"}