docs: update Claude Code releases to v2.1.31

- Update latest tracked version: v2.1.29 → v2.1.31
- Add v2.1.31 highlights: Session resume hint, PDF/bash/LSP fixes, system improvements
- Add v2.1.30 highlights: PDF pages support (pages parameter), OAuth pre-config (Slack), /debug command, git flags, task metrics
- Update dates: 2026-02-02 (v2.1.30), 2026-02-03 (v2.1.31)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

machine-readable/claude-code-releases.yaml

@@ -3,8 +3,8 @@
 # Purpose: Track Claude Code product releases for documentation sync
 # Maintained: Manual updates when new releases are announced
 
-latest: "2.1.29"
-updated: "2026-02-02"
+latest: "2.1.31"
+updated: "2026-02-04"
 
 # ════════════════════════════════════════════════════════════════
 # RELEASES (newest first, condensed highlights only)
@@ -12,9 +12,27 @@ updated: "2026-02-02"
 releases:
 
   # ─────────────────────────────────────────────────────────────
-  # 2.1.x Series (January 2026)
+  # 2.1.x Series (January-February 2026)
   # ─────────────────────────────────────────────────────────────
 
+  - version: "2.1.31"
+    date: "2026-02-03"
+    highlights:
+      - "Session resume hint on exit showing how to continue"
+      - "Fixed PDF errors locking sessions & bash sandbox errors"
+      - "LSP compatibility improvements & terminal rendering fixes"
+    breaking: []
+
+  - version: "2.1.30"
+    date: "2026-02-02"
+    highlights:
+      - "`pages` parameter for Read tool PDFs (e.g., `pages: '1-5'`)"
+      - "Pre-configured OAuth for MCP servers (Slack support)"
+      - "⭐ `/debug` command for session troubleshooting"
+      - "git log/show read-only flags support"
+      - "Task tool metrics (tokens, duration, tool uses)"
+    breaking: []
+
   - version: "2.1.29"
     date: "2026-01-31"
     highlights: