v0.82.0: X-Felhom-Agent-Version response header — the controller capability channel

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6

CHANGELOG.md

@@ -1,3 +1,15 @@
+## v0.82.0 — local-API version channel: X-Felhom-Agent-Version on every response (2026-07-11)
+
+The controller's capability detection upgrades from route-probing to version comparison: the
+local-API mux is wrapped so EVERY response (any route, any status, including auth failures) carries
+`X-Felhom-Agent-Version` = the build version (`localapi.Options.AgentVersion`, wired from
+main.version). The controller (v0.115.0) reads it passively from ordinary traffic and compares it
+against a per-feature MinAgent table; header-less (≤0.81.0) agents keep working — the controller
+falls back to the v0.114.0 route probe unchanged. No new routes, no envelope changes, no sudoers
+changes. Test: header asserted on authed/unauthed/404 responses (red-proof: wrap dropped → fails);
+empty version emits NO header. Demo-deploy only — NOT published (Peti stays 0.81.0 = the live
+fallback path).
+
 ## v0.81.0 — NAS verify-before-commit: retry=0 + detached verify job + journal classification (2026-07-11)
 
 Implements the agent half of the "NAS verify-before-commit" task on the SPIKE-nas-verify-2026-07-11