feat(cli): filter agents by name in console

[codeaholicguy]

Summary

• add a vim-style / inline agent-name filter with case-insensitive substring matching
• highlight every visible match while preserving source order, selection, navigation, counts, remote markers, and empty/error states
• pause agent and channel polling while editing or while a filter is applied; Esc clears and refreshes immediately
• keep command characters literal during editing, make Enter confirm, and keep / a no-op for confirmed filters

Design source

• docs/ai/design/2026-08-16-feature-agent-list-filter.md
• docs/ai/requirements/2026-08-16-feature-agent-list-filter.md

Validation

• focused console suite: 6 files, 35 tests passed
• pure matcher coverage: 100% statements, branches, functions, and lines
• key-routing coverage: 100% statements, branches, functions, and lines
• CLI tests: 83 files, 1001 tests passed
• CLI lint: exit 0 (five pre-existing warnings)
• CLI build: SWC compilation and TypeScript declarations succeeded
• npx ai-devkit@latest lint --feature agent-list-filter: passed

Risks

None known. The filter consumes the incoming ordered agent array and contains no pin-specific ordering logic.