Add read-only trip summary widget

[raykellyjr]

Adds a read-only home screen Trip summary widget backed entirely by cached Room summaries. It never sends vehicle commands or polls the car.

Highlights:

• Vehicle selection with reconfigurable 7/30/90-day ranges
• Distance, drives, driving days, energy, efficiency, charging cost, and cost per 100 distance units
• Same-length previous-period distance comparison
• Honest charging-cost coverage labels for missing, partial, and complete price data
• Periodic/offline updates plus refresh after successful data sync
• Trips deep-linking without live car polling
• Cached TeslaMate unit and currency handling
• Localized widget copy in English, Catalan, German, Spanish, Italian, and Chinese
• Formatter and date-range unit coverage

Local verification:

• git diff --check
• ./gradlew :app:testDebugUnitTest :app:lintDebug :app:assembleDebug

Local setup note: Android SDK, Gradle cache, and build output are backed by an APFS sparsebundle on the external SSD to avoid internal disk pressure.

[raykellyjr]

Freshly revalidated this branch on 2026-07-16:

• :app:testDebugUnitTest passes
• :app:lintDebug passes
• :app:assembleDebug passes
• branch remains mergeable and current with main

The new widget reads cached Room summaries only; it does not send vehicle commands or trigger live car polling. I am happy to adjust or split the change if a smaller review surface would be preferable.

[raykellyjr]

Polished this branch for cost honesty and fresher unit/currency labels:

• Cost/100 now only appears when every charge in the selected range is priced
• Known totals still show under partial coverage, including compact mode (Cost $x · 1/2 priced)
• Widget refreshes immediately after currency changes and when TeslaMate unit-of-length is cached
• Changelog + README updated for the second widget
• Formatter/ViewModel unit tests updated; lint + targeted unit tests pass

Still fully read-only over cached Room data — no vehicle commands or live car polling.

[raykellyjr]

Still complementary to #334 — #334 adds the Cost summary widget + Cost Analytics screen; this Trip summary widget remains a separate read-only home-screen surface.

[raykellyjr]

Review + polish pass complete

Self-reviewed and pushed follow-up fixes:

• No longer relabels cached Room summaries with a new unit before re-sync (avoids km data shown as mi)
• Worker resolves units from TeslaMate global settings before formatting
• Widget refreshes when summaries land even if later detail sync retries
• Cost honesty unchanged: cost/100 only when every charge in range is priced

Local verification: targeted unit tests + lint green.

CI note: please approve the workflow run (action_required for fork PRs) so CI can execute.

[raykellyjr]

Final correctness pass: trip widget labels now use the unit cached at summary-sync time only (no live settings fetch during widget update). Ready for workflow approval.