test(gmail): close #1503's patch-coverage gaps in sync's live-progress and reconciliation paths

[newhoggy]

Summary

• feat(gmail): pipeline sync's listing/fetch phases and add live multi-bar progress #1503's coverage bot flagged four patch-coverage gaps that landed uncovered when it merged (comment: feat(gmail): pipeline sync's listing/fetch phases and add live multi-bar progress #1503 (comment)). This closes all four:
  • run_sync_command's show_progress branch (sync.rs:130-142) was structurally untestable — it called std::io::stderr().is_terminal() directly instead of taking it as a parameter, unlike should_show_progress which already does this for exactly this reason. Threaded a stderr_is_terminal: bool param through so a test can force the live-progress path.
  • LoadOutcome::Present + opts.full == true (engine.rs:159-168, forces reconciliation despite a valid watermark) was untested.
  • LoadOutcome::Corrupt (engine.rs:186-195, a malformed state.json triggers reconciliation rather than a hard error) was untested.
  • fetch_and_archive_messages_streaming's duplicate-id dedup (engine.rs:458, a page-boundary race in the live-streamed listing) was untested.
• The coverage bot's "indirect changes" section also flagged engine.rs:579-582 (inside fetch_and_archive_messages, used only by run_incremental) as losing coverage on code feat(gmail): pipeline sync's listing/fetch phases and add live multi-bar progress #1503 never touched, with no test removed either — most likely CI measurement noise rather than a real gap, so left as-is.

Test plan

• cargo build --lib --tests --features mcp
• cargo test --features mcp --lib cli::gmail::sync:: (77 passed)
• cargo clippy --tests --features mcp -- -D warnings

[github-actions]

Coverage

Total: 97.33% 🟢 0.03 pp vs main

Comparing 20b45cc..c71ee77 (merge-base → PR head)

File	Before	After	Δ
src/cli/gmail/sync.rs	97.79%	99.28%	🟢 1.5 pp
src/cli/gmail/sync/engine.rs	97.25%	99%	🟢 1.75 pp

Patch coverage

Patch: 100% (160/160 new lines covered)

File	Patch	Uncovered new lines
src/cli/gmail/sync.rs	100% (62/62)	—
src/cli/gmail/sync/engine.rs	100% (98/98)	—

Indirect coverage changes

🔴 0 lines lost coverage, 🟢 34 lines gained coverage on unchanged code.

Indirect changes

• src/cli/gmail/sync.rs:138 🟢 uncovered → covered
• src/cli/gmail/sync.rs:139 🟢 uncovered → covered
• src/cli/gmail/sync.rs:140 🟢 uncovered → covered
• src/cli/gmail/sync.rs:141 🟢 uncovered → covered
• src/cli/gmail/sync.rs:145 🟢 uncovered → covered
• src/cli/gmail/sync.rs:148 🟢 uncovered → covered
• src/cli/gmail/sync.rs:149 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:154 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:158 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:159 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:160 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:161 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:162 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:163 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:164 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:165 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:166 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:167 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:168 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:182 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:183 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:184 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:185 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:186 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:187 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:188 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:189 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:190 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:191 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:192 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:193 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:194 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:195 🟢 uncovered → covered
• src/cli/gmail/sync/engine.rs:458 🟢 uncovered → covered

_{📦 Full per-file coverage summary · run summary}