🐛 fix: rewrite flattened import paths after component install

[renardeinside]

Summary

• Fixes 🐛 [BUG] mcp add_component: internal imports not rewritten to match flattened file paths #88: cross-file imports inside installed components were left pointing at the original nested registry paths (e.g. @/components/animate-ui/icons/icon) after file flattening flipped the saved name to icons-icon.tsx
• Adds build_path_map to compare each file's original registry path against its saved (flattened) path and collect the differences
• Adds rewrite_flattened_paths to apply that map to file content, anchored on the trailing quote to prevent partial-prefix matches; longest paths win

How it works

When plan_add resolves a component closure it now:

1. Builds an original → saved path map across all resolved files
2. Chains rewrite_flattened_paths after rewrite_registry_imports when writing each file

Helper functions added:

Function	Purpose
determine_output_root	Replaces the inline match file_type in the loop
compute_saved_import_path	@/components/{registry}/{resolved.name} etc.
original_registry_import_path	Strips extension, prepends @/ to file.path
build_path_map	Collects original→saved pairs where they differ
rewrite_flattened_paths	Quote-anchored, longest-first string replacement

Test plan

• 9 new unit tests added in components::tests (component rewrite, hook rewrite, deeply-nested rewrite, no partial-match, empty map, path stripping, map building, integration scenario)
• All 137 apx-core lib tests pass
• cargo fmt --check passes
• cargo check passes

🤖 Generated with Claude Code