fix(web): show launch times in local and UTC with explicit labels

[ItsCalebJones]

Reported by a site visitor: launch times on /launch/upcoming/ carry no timezone label and appear to alternate between UTC and viewer-local. They missed launches because of it.

Cause

django-tz-detect activates the session timezone only from the second page view onward — its own README states "Django's timezone awareness will not be available on the first page view." So the first view renders UTC, later views render viewer-local, and an expired session or blocked JS silently reverts to UTC. Nothing on the page said which.

Change

All launch times now render client-side from a UTC ISO-8601 instant through one shared {% launch_time %} tag: local time primary, UTC beneath, both labeled.

• The precision → display-shape mapping lives in Python, where CI can test it. launch-time.js is left with a single unconditional path.
• Coarse precisions ("Q3 2026", "During the 2020s") get no timezone and no UTC line — attaching one would claim precision the data lacks.
• The server emits a fully-rendered labeled UTC fallback, so crawlers and no-JS visitors see a correct time. Previously #date was emitted empty for JS to fill.

Also fixed

• Mobile launch detail showed no date at all — #date was empty in all three branches and the only code filling it was commented out, passing {{ launch.net }} where a precision ID belongs.
• index, index_mobile and app each overwrote #date via dateFormat(...), which would have clobbered the new markup.
• LaunchListView gained select_related — the new NET column reads net_precision, and that page already N+1'd on its other FK columns.

Removed

django-tz-detect, moment-timezone.min.js (~180KB), dateFormat.js, and three verbatim copies of getDateFormat. moment.min.js stays — the datetimepicker needs it.

Side benefit: dropping per-session timezone activation makes these pages cacheable again.

Verification

Locally: 11/11 new launch-time tests pass, ruff clean across src/, all edited templates parse, poetry check --lock clean.

Docker was unavailable locally, so the DB-backed regression tests and the rest of the suite run here in CI for the first time.

Spec: docs/superpowers/specs/2026-08-11-launch-time-display-design.md

🤖 Generated with Claude Code

[github-actions]

🔍 Quality Check Results

Check	Status	Result
🔍 Linting	✅	success
🧪 Testing	✅	success
🔒 Security	✅	success

🎉 All quality checks passed! This PR is ready for review.

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_{Triggered by commit af315ef • View Details}