test: dedupe shared test setup (console spies, program, channel fixture)

[scottlovegrove]

Summary

Audit + dedupe of repeated test scaffolding across the suite. Three focused commits, each its own concern:

• captureConsole() (src/test-helpers/console.ts) — replaces ~209 inline vi.spyOn(console, ...).mockImplementation(() => {}) spies across 25 files and removes ~159 manual mockRestore() calls (auto-restores via onTestFinished).
• createTestProgram(register) (src/test-helpers/program.ts) — collapses 24 identical local createProgram() definitions; call sites unchanged via a one-line wrapper. Drops now-unused commander imports.
• createChannelFixture() (src/lib/__fixtures__/channels.ts) — replaces 4 byte-identical sampleChannel literals (channel add/remove/set/members), matching the existing accounts-fixture pattern.

Net: −367 lines (29 files), no behavior change.

Deliberately not done

• makeTwistClientMock — the per-command client mocks are each a different SDK subset; a generic helper would be a no-op {...overrides} wrapper (premature abstraction).
• Shared apiMocks/refsMocks factories — real dup exists in the 4 channel-membership files, but vi.hoisted runs before imports so a shared factory can't be imported into it (TDZ); the __mocks__/ alternative would force all 16 api-mocking files onto one global mock surface.
• Single-use entity factories (thread/message/comment/conversation) left in place — relocating them wouldn't reduce duplication.

Test plan

• npm run type-check clean
• npm run lint:check clean
• npm test — 677 passed (43 files)

🤖 Generated with Claude Code

[doistbot]

This PR effectively cleans up the test suite by deduplicating console spies, program initialization, and channel fixtures into shared helpers. This provides a great boost to maintainability by dropping nearly 400 lines of boilerplate while thoughtfully avoiding premature abstractions. A few minor adjustments are needed to ensure the new test helpers directory is properly excluded from the published build output and to strictly type the channel fixture overrides so we maintain the safety of the original inline literals.

_{Share Feedback • Review Logs}