feat(components): add client-side search to project Skills tab

[Pleasurecruise]

Related issue

Closes #212

Problem / pressure

Projects can expose hundreds of skills, but the Skills tab had no way to narrow the list.

Summary

• Add client-side search across skill name, description, author, and path.
• Preserve directory grouping and show a dedicated no-results state.

Before / after

Before	After
Finding a skill required scrolling through every group.	Typing in the search field filters matching skills in place.

Test plan

• corepack pnpm format
• corepack pnpm --filter @lody/components typecheck
• corepack pnpm lint
• corepack pnpm lint:i18n
• corepack pnpm --filter @lody/components test — 402 files / 2,894 tests passed.
• Not run: full pnpm check and pnpm check:quick.

Context handoff

Instructions for reviewing agents

• Review focus: Check the filtering and no-results branches in project-skills-tab.tsx without regressing existing loading and error states.
• Decisions to challenge: Confirm case-insensitive substring matching across visible metadata is sufficient instead of fuzzy search.
• Plausible failures / evidence gaps: The filter has no focused unit test; verification relies on package tests, typechecking, and manual UI coverage.

Authoring context

• User goal / directives: Add a compact search field to Projects > Skills for lists containing hundreds of skills.
• Constraints / non-goals: Keep the change client-side and scoped to the existing view; skill discovery, RPC, and fuzzy ranking stay unchanged.
• Risk-bearing decisions: Empty groups are removed only from filtered rendering; source skill data is never mutated.
• Destructive or irreversible behavior: The change adds no persistence, migration, deletion, or external write behavior.
• Deliberately not done or tested: No focused filter unit test or full workspace check was added; targeted component validation covered the changed surface.
• Unknowns / confidence: Confidence is high for the narrow UI change; reviewer judgment is requested on whether substring matching is sufficient.