Stamp CHANGELOG for v0.51.134 (Release DF / stage-batch16)

Single-PR Windows-paths align fix:
- PR #2897 (chouzz) — align WebUI default state/config paths with Hermes Agent's
  %LOCALAPPDATA%\hermes on Windows. POSIX behavior unchanged.

Cherry-picked clean from contributor tip to dodge stale-base trap (net master→PR
delta was -2184 LOC due to ~2-week-old base).

Gates passed:
- Pre-Opus: Python ast.parse on api/config.py, api/profiles.py, new test file
- Stale-base check: cherry-picked diff matches contributor's actual change (6 files, +55/-17)
- Opus advisor: SHIP-AS-IS, Linux no-op invariant verified
- Full pytest sequential: 6540 passed, 6 skipped, 3 xpassed, 0 failures (179s)

Closes #2840.

CHANGELOG.md

@@ -3,6 +3,8 @@
 
 ## [Unreleased]
 
+## [v0.51.134] — 2026-05-25 — Release DF (stage-batch16 — single-PR Windows path defaults)
+
 ### Fixed
 
 - **PR #2897** by @chouzz — On Windows, WebUI default state and config paths now align with Hermes Agent's `%LOCALAPPDATA%\hermes` convention instead of `%USERPROFILE%\.hermes`, so a fresh Windows install finds the same `~/.hermes/config.yaml` / `auth.json` / `webui/` state directory that the Hermes Agent created. POSIX behavior is unchanged (`~/.hermes` remains the default). `HERMES_HOME` and `HERMES_WEBUI_STATE_DIR` env overrides take precedence on both platforms. Closes #2840.