feat(go): port FIM/pkgdb/rootcheck integrity engines and add go-sidecar dashboard consumer

Adds sidecar-only, --state-dir-gated FIM, package-DB-anchor, and rootcheck
engines to the Go migration sidecar, wired into agent.Sweep/Initialize
behind the existing baseline lifecycle. Adds a read-only, schema-checked
Python dashboard consumer (go_sidecar_state_dir, /api/go-sidecar/*, Sidecar
tab) that never starts, stops, or mutates the Go sidecar's state.

Also fixes drift found while reconciling this work: enodia_sentinel/web.py
had reinvented local schema constants instead of using the canonical
enodia_sentinel/schemas.py catalog (now registers enodia.go.sidecar.v1
there and reuses ALERT_SNAPSHOT_V1/INCIDENT_V1); docs/RULES.md had drifted
from what `rules docs` actually generates for SIDs 100069-100078 (ruleops.py
was missing metadata for four SIDs and had stale drill text for four more),
now back in sync with a regression test pinning them together.

Updates CLAUDE.md, README.md, go-agent/README.md, and docs/{ROADMAP,
GO_PORT_HANDOFF,SURICATA_ASSIMILATION,THREAT_MODEL,OPERATIONS,SCHEMAS,
COMMAND_REFERENCE}.md to reflect the landed work.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NQivSKBqQJsayz1xcYqWzZ

README.md

@@ -430,6 +430,10 @@ sudo systemctl enable --now enodia-sentinel-web
   API at `/api/status`, `/api/incidents`, `/api/respond/plan/<id>`,
   `/api/posture`, `/api/integrity`, `/api/rules`, `/api/alerts`,
   `/api/alerts/<id>`, `/api/events`.
+- **Optional Go migration evidence**: set `go_sidecar_state_dir` to the
+  sidecar's separate state directory to expose retained heartbeat, snapshots,
+  incidents, and JSONL through `/api/go-sidecar/*`. These endpoints are
+  read-only and never replace Python dashboard data or control the sidecar.
 - **Operator settings**: the self-contained dashboard includes a Settings menu
   with persistent local themes: Console, Paper, Contrast, LGBTQ, Trans, Dracula,
   Solarized Dark, Solarized Light, and Twilight. Static dashboard tests guard