chore(release): v3.14.0 — security hardening (sessions namespacing + file modes + /api/usage scope) (#89)

Bump version 3.13.0 → 3.14.0. No functional code change in this PR;
all three security fixes are already merged in main via PRs #86, #87, #88.

This PR covers only metadata + docs:
- package.json: version bump to 3.14.0
- CHANGELOG.md: v3.14.0 entry with Features / Behavior changes / Verification /
  Governance sections
- README.md: /api/usage self-scope note in Auth Modes §, API Endpoints table
  row update, file-mode bullet in Important Notes §

cli.js citation N/A: this release PR modifies no server.mjs / setup.mjs / keys.mjs.
The three underlying security PRs (#86, #87, #88) each carry their own
cli.js-citation-not-applicable disclaimer per PR #75 pattern, as they are
OCP-internal access-control, session-state, and file-permission changes with
no corresponding cli.js operation.

Co-authored-by: dtzp555 <dtzp555@gmail.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "open-claude-proxy",
-  "version": "3.13.0",
+  "version": "3.14.0",
   "description": "OCP (Open Claude Proxy) — use your Claude Pro/Max subscription as an OpenAI-compatible API for any IDE. Works with Cline, OpenCode, Aider, Continue.dev, OpenClaw, and more.",
   "type": "module",
   "bin": {