capability: agent privileged-capability self-probe (manifest + build-test + runtime snapshot) v0.44.0

New internal/capability: Manifest of required sudo -n grants + Prober that LISTS each
via 'sudo -n -l' (never executes) + binary-exists check → ok/degraded snapshot on the hub
report. Build-time test asserts manifest⊆sudoers (red-proof: dropping lxc-info FAILs the
gate). Startup logs N/N ok + ERROR per degraded. Serve-degraded; no allowlist change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EPZ4GJ8L5Jqf8UiPwbn1kt

CHANGELOG.md

@@ -3,7 +3,34 @@
 All notable changes to **felhom-agent** are recorded here. Update on every code
 change that gets pushed.
 
-## (unreleased) — sudoers completeness audit: close non-root allowlist gaps (no binary change) (2026-06-29)
+## v0.44.0 — privileged-capability self-probe (build-time manifest test + runtime probe + hub snapshot) (2026-06-29)
+
+The agent now self-checks the `sudo -n` grants it depends on, so a missing allowlist entry (the
+2026-06-28 cutover class: lxc-info/make-private/…) is caught LOUD — in CI at build time and on the
+host at runtime — instead of surfacing days later as user-visible breakage. **First slice of agent
+self-health; the controller↔agent channel check is a separate later task.**
+
+- **`internal/capability` (NEW):** a `Manifest()` of the required `(binary, representative-arg)`
+  vectors (seeded from the 2026-06-29 audit — the OK + CLOSED rows; the SURFACED/DEFERRED rows
+  `pct exec *`/`pct create`/`mount UUID`/`sensors` are deliberately excluded). `Prober.Probe` lists
+  each against the live policy with `sudo -n -l -- <binary> <args>` (a policy LIST — **never
+  executes**, safe for mkfs/pct entries) via a DIRECT runner, plus an `os.Stat` existence check,
+  mapping to `ok` / `degraded` ("sudo policy denied" | "binary not found"). A total sudo failure
+  (drop-in missing) collapses to ONE aggregate signal. Serve-degraded: the probe never blocks
+  startup, panics, or errors.
+- **Build-time gate (`manifest_test.go`):** parses `configs/felhom-agent.sudoers`, translates each
+  glob to a regex, and asserts **every manifest vector is covered by a grant** — exactly what would
+  have caught the dropped `lxc-info`/`make-private` lines in CI. Includes a **red-proof**: with the
+  `lxc-info` line removed from an in-memory copy, the check FAILS for `guest-init-pid` (and passes
+  on the real file) — proving the gate is not hollow.
+- **Runtime wiring:** `Probe` runs once at startup (INFO `capabilities self-check N/N ok`, plus an
+  ERROR per degraded capability naming the gated feature) and on every hub-report cycle; the snapshot
+  rides the report as the new non-nil `HostReport.Capabilities []capability.Status` (golden +
+  contract test updated; cross-repo hub copy mirrors it).
+- **No allowlist change**; the live host is post-audit complete, so the probe reports N/N ok — itself
+  a live proof the probe agrees with the fixed sudoers. Version `0.43.0 → 0.44.0`.
+
+## (sudoers completeness audit, folded into v0.44.0) — close non-root allowlist gaps (2026-06-29)
 
 A full audit of every privileged command the agent shells via `sudo -n` against
 `configs/felhom-agent.sudoers`, closing the read-only/fixed-vector gaps left by the 2026-06-28