v2.5.1-budget-100: raise all tool call budgets to 100 + codecontextignore fix

Budget defaults raised from 50/10/50 to 100/100/100 (read-only,
non-read-only, no-agent). Per-agent max_tool_calls from AGENTS.md
still overrides.

Added .claude/worktrees/ to .codecontextignore to prevent
get_codebase_overview from parsing empty stub files in stale
worktree node_modules.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.codecontextignore

@@ -21,6 +21,7 @@ out/
 .opencode/
 .vscode/
 .idea/
+.claude/worktrees/
 
 # Test artifacts / coverage
 coverage/