feat: automatic project type and framework detection (#293)

Add SessionStart hook integration that auto-detects project languages
and frameworks by inspecting marker files and dependency manifests.

Supports 12 languages (Python, TypeScript, Go, Rust, Ruby, Java, C#,
Swift, Kotlin, Elixir, PHP, JavaScript) and 25+ frameworks (Next.js,
React, Django, FastAPI, Rails, Laravel, Spring, etc.).

Detection output is injected into Claude's context as JSON, enabling
context-aware recommendations without loading irrelevant rules.

- New: scripts/lib/project-detect.js (cross-platform detection library)
- Modified: scripts/hooks/session-start.js (integration)
- New: tests/lib/project-detect.test.js (28 tests, all passing)

Co-authored-by: Claude <noreply@anthropic.com>

tests/run-all.js

@@ -15,6 +15,7 @@ const testFiles = [
   'lib/package-manager.test.js',
   'lib/session-manager.test.js',
   'lib/session-aliases.test.js',
+  'lib/project-detect.test.js',
   'hooks/hooks.test.js',
   'hooks/evaluate-session.test.js',
   'hooks/suggest-compact.test.js',