[foundation] Add consolidation API to InstallStateManager

Parent Issue

Part of #193 - Consolidate install-state.json manipulation with InstallStateManager

Summary

Add methods to InstallStateManager in amplifier-foundation to support consolidation of install-state.json manipulation.

Scope: amplifier-foundation

File: amplifier_foundation/modules/install_state.py

Changes Required

New Methods

1. invalidate_modules_with_missing_deps() -> tuple[int, int]

   • Surgically invalidate only modules whose dependencies are missing
   • Check each tracked module's declared dependencies against what's installed
   • Returns (modules_checked, modules_invalidated) for reporting
   • Useful after uv tool install --force wipes the venv

2. clear() -> None

   • Convenience method for full state reset
   • Equivalent to invalidate(None)

Enhanced Behavior

3. Enhance is_installed() to verify dependencies
   • Proactively check that declared dependencies are actually present
   • Auto-heal stale state by invalidating entries with missing deps
   • Catches stale state without needing explicit cleanup calls

Helper Functions (module-level)

4. _extract_dependencies_from_pyproject(path) -> list[str]

   • Parse pyproject.toml for dependency names

5. _check_dependency_installed(dep_name) -> bool

   • Use importlib.metadata with PEP 503 name normalization

Acceptance Criteria

• invalidate_modules_with_missing_deps() correctly identifies modules with missing deps
• clear() resets all module state
• is_installed() returns False when dependencies are missing (proactive self-healing)
• All existing tests pass
• Shadow test verifies auto-healing works end-to-end

Benefits

• Users stuck in stale state auto-recover on next session start
• Provides clean API for app-cli to use instead of direct JSON manipulation
• Enables follow-up work in #194

Start with amplifier_foundation/modules/install_state.py and trace the existing invalidate() and is_installed() behavior. Review the dependency requirements in the issue and run the existing test suite before adding coverage for missing dependencies, clear(), and the end-to-end shadow test. Done means the acceptance criteria pass and all existing tests remain green.