chore(tui): restore ESLint rules and verification gate

[hetaoBackend]

Change

The public TUI had no ESLint configuration, dependencies, lint command or verification gate, so source-policy violations could pass CI. Add pnpm lint / pnpm lint:tui for TUI source and tests and run the gate through the shared verifier, including full, platform, archive and Windows profiles.

Adapt the source repository's Airbnb-base, TypeScript, import and Prettier policy, retaining the audited Pi engine's narrow exceptions and warning severities. Pin the existing source toolchain (ESLint 8.57.1 / TypeScript ESLint 7.18.0) for rule parity; a toolchain upgrade is separate work. React/browser rules are outside this Node TUI scope. The scripts use --quiet to suppress existing warning output without changing rule severity; invoke ESLint directly without it to inspect warnings. Upstream Pi test copies are excluded, while first-party tests are checked.

Fix 13 existing errors with local renames, equivalent expressions, merged imports and one documented test-only packaging import exception. Add regressions for rule enforcement, test coverage, engine/facade exceptions and verifier failure propagation. Update contributor guidance, the development skill, dependency licenses and source inventory.

Validation

• PASS: pnpm verify on clean commit 151fc6266189c5796c5f97b5271bf54fd59503e9, full profile, macOS arm64 / Node 26.4.0: all 15 applicable gates in 180 seconds. Capability suite: 172 files, 4,585 tests passed, 14 skipped under existing conditions.
• PASS: frozen offline installation, standalone pnpm lint, lint contract regressions and git diff --check.
• PASS: Gitleaks on complete HEAD ancestry (101 commits) and exported source, using the repository configuration.
• Performance: basic; no performance optimization or runtime pipeline change.
• NOT RUN locally: native Linux/Windows, live services and npm release archive installation. Remote CI remains separate evidence.

Publication and contribution checks

• Existing applicable licenses and source provenance preserved; only the reviewed TUI lint policy is adapted.
• No credentials, account data, real user content, internal history or private review material included.
• New config reviewed before regenerating the inventory; regression coverage belongs to the existing release-tools suite.
• English contributor guidance and the verification skill updated; offline results are not live-service acceptance.

Maintainer handoff

Publication scope: one ESLint configuration plus development-only dependencies. Shared-source port: not needed for distribution-specific verification wiring; lint cleanup can be ported through the normal public-to-source process.

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