fix(data): backfill 37 confirmed GSMArena URLs via verify tool

[Seungpyo1007]

What

Retry of the GSMArena backfill (the 2026-09-23 rate limit had long expired).
Upgrades kaggle-only smartphone records (Tier 3, variant.source_category == "gsmarena-kaggle") to a confirmed GSMArena Tier-2 spec-page URL, using the
existing app.verify.gsmarena_backfill tool in TechEngine. The tool's strict
multi-signal gate (sitemap identity + heading match + liveness + spec agreement
on battery/RAM/display/weight) decides every write; AMBIGUOUS / NOTFOUND /
CONTRADICT are reported, never written. Matches were not hand-authored and the
gate was not loosened.

37 records received a confirmed source_urls upgrade before the run was
stopped by a fresh rate limit (see below). Commits:

1. fix(data): backfill 37 confirmed GSMArena URLs via verify tool — the
   data/smartphone/** source_urls edits.
2. chore(dump): refresh smartphone dump pages for GSMArena URL backfill — the
   mandatory dump refresh (python -m app.dump from a TechEngine checkout, fresh
   scratch DATABASE_URL, TECHAPI_DATA_DIR pointed at this worktree). Only the
   37 affected site/public/v1/smartphones/<slug>/index.json detail pages
   changed; unrelated score-percentile/schema churn from a fresh full dump was
   excluded so this PR carries only the backfill's effect.

Rate limit (run stopped early, not retried)

The apply run made real progress (the 37 confirmed writes above) and then hit a
GSMArena 429 with Retry-After: 36000s (10 hours). The tool stopped cleanly
before sending any further requests — no retry spinning — and left the remaining
kaggle-only records eligible for a later invocation. A dry-run of 20 immediately
beforehand was clean (19 CONFIRM / 1 NOTFOUND, no 429), so the limit was tripped
during this apply run rather than being a pre-existing block.

Unresolved this run (correctly not written): Caterpillar B15 (NOTFOUND,
no-index-hit), Lenovo A60+ (AMBIGUOUS, ambiguous-index), Sharp Aquos Crystal 2 (NOTFOUND, not-live).

Tool summary

# GSMArena backfill

- records: 57 across 57 brands
- index phones: 13849
- http requests this process: 37
- sleep between requests: 1.5s
- resumed from cache: 20
- dry-run: False

## Decisions

| decision   | count | ratio |
| ---------- | ----: | ----: |
| CONFIRM    |    54 | 94.7% |
| AMBIGUOUS  |     1 |  1.8% |
| NOTFOUND   |     2 |  3.5% |
| CONTRADICT |     0 |  0.0% |

(54 CONFIRM proposed across this run's window; 37 resulted in a new working-tree
write — the remainder already carried the confirmed URL from a prior session's
cache, so the idempotent write guard left them untouched.)

Verification

• python -m app.validate (bundled validator) — ✅ Data validation passed.
• Dump regenerated with python -m app.dump; the 37 committed detail pages are
  clean source_urls appends matching the data edits.

Closes #296