chore: improve agent readiness — AGENTS.md, dependabot, CODEOWNERS, labels

- Add AGENTS.md with build commands, project structure, conventions
- Add .github/dependabot.yml for automated pip + actions updates
- Add .github/CODEOWNERS for review routing
- Expand .gitignore (.env, .DS_Store, IDE configs, coverage, venvs)
- Add C901 complexity rule to ruff (max-complexity=25, benchmarks excluded)
- Add --durations=10 to pytest CI for test performance tracking
- Add docs/schema.sql for knowledge graph schema documentation
- Created P0-P3 priority + area/* + security/performance/docs labels

pyproject.toml

@@ -54,11 +54,15 @@ packages = ["mempalace"]
 [tool.ruff]
 line-length = 100
 target-version = "py39"
+extend-exclude = ["benchmarks"]
 
 [tool.ruff.lint]
-select = ["E", "F", "W"]
+select = ["E", "F", "W", "C901"]
 ignore = ["E501"]
 
+[tool.ruff.lint.mccabe]
+max-complexity = 25
+
 [tool.ruff.format]
 quote-style = "double"