v0.115.0: version-aware Supports (agent header channel) + DSM-validated NFS guidance — MinAgent: 0.81.0

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

CHANGELOG.md

@@ -1,5 +1,34 @@
 ## Changelog
 
+### v0.115.0 — version-aware Supports (agent version channel) + DSM-validated guidance (2026-07-11) — MinAgent: 0.81.0
+
+Capability detection upgrades from route-probing to explicit version comparison, riding agent
+v0.82.0's `X-Felhom-Agent-Version` response header. **The probe FALLS BACK cleanly — agent 0.82 is
+NOT required** (MinAgent stays 0.81.0: the coupled NAS semantics; Peti's 0.81.0 box exercises the
+fallback in production).
+
+- **agentapi**: every response path passively captures the header (`noteAgentVersion` on all four
+  `Do` sites — even on 404s/errors); STRICT bare-semver validation at capture (the publish-agent.sh
+  shape; garbage never overwrites); `Client.AgentVersion()` exposes the last-seen value.
+- **features.go**: per-feature `featureMinAgent` table (`netstorage_verify: 0.81.0`) + optional
+  `AgentVersionReporter` on the prober. `Supports` order: version known → semver compare →
+  Yes/No with ZERO probe traffic; version unknown/garbage/table-gap → the v0.114.0 probe path
+  byte-identical (SupportCache stays probe-only). Gate/banner/UI unchanged — same three verdicts,
+  better source.
+- **THE one comparator**: `selfupdate.ParseVersion/Version.Compare` moved verbatim to
+  `internal/util/version.go` (selfupdate keeps type aliases — call sites + tests byte-unchanged);
+  agentapi shares it (no import cycle, no second comparator).
+- **DSM-validated NAS guidance** (SPIKE-nas-dsm-2026-07-11, real DSM 7.2 via virtual-dsm): the NFS
+  guidance gains the verified Synology steps — File Services → NFS → enable + **Maximum NFS
+  protocol: NFSv4.1** (the v3 default refuses our mount), NFS Permissions rule with Squash
+  „Map all users to admin”, the `/volume1/<mappa>` path hint; the "útmutató készül" caveat narrows
+  to **QNAP only** (Synology now validated end-to-end incl. SMB hardlink).
+- Tests + red-proofs: version-known compares without probing (mutant: short-circuit dropped →
+  probes=1); garbage/absent header → exactly-one-probe fallback + cached (mutant: trusting an
+  unparseable header as "too old" → fails); non-reporter probers byte-unchanged; comparator table
+  incl. pre-release rejection + numeric-vs-lexicographic; wire-level: header wins over a routeless
+  agent through the real pinned client, garbage header ignored at capture.
+
 ### v0.114.0 — agent-capability gate for coupled features (2026-07-11) — MinAgent: —
 
 Box-level backstop for the publish-train ordering discipline (incident: the 0.81/0.113 train's