fix(data): resolve 45 generic SoC placeholder references (Google Pixel)

[Seungpyo1007]

Summary

Resolves a subset of generic/placeholder soc references on device records by
re-pointing them to the correct, specific SoC records that already exist in
data/soc/. Scoped to the cases that are unambiguously determinable and
fully sourced — the Google Pixel line — and documents the much larger
remainder that cannot be repaired without per-record web sourcing (which would
mean inventing values at scale, contrary to project policy).

Scope characterized (fresh scan of current develop)

Three genuine placeholder SoC records account for essentially all the
placeholder soc references across smartphone/tablet/watch/pda:

Placeholder SoC record	Path	Device refs
0 (name "0", raw_chipset "0")	data/soc/arm/2014/0.json	3,610
qualcomm-snapdragon (bare family, no model)	data/soc/qualcomm/2011/qualcomm-snapdragon.json	1,762
n-a (name "N/A")	data/soc/arm/2008/n-a.json	273

Total: 5,645 device references across ~2,793 distinct base models. Every one
of these placeholder records carries the tell-tale signature: verified: false,
a single generic source (kaggle GSMArena dump / phonedb), and
"Unknown mobile GPU" / "N/A" fields.

What was fixed (45 records)

Google Pixel phones ship a single global SoC per model (no regional
Exynos/Snapdragon split), so the chip is unambiguous and documented on each
model's Wikipedia page. I re-pointed 45 Pixel smartphone variants off the
placeholders to the correct existing Snapdragon records:

Pixel model	→ SoC record	count
Pixel (2016)	snapdragon-821	1
Pixel 3	snapdragon-845	1
Pixel 3a / 3a XL (+ region variants)	snapdragon-670	29
Pixel 4 / 4 XL	snapdragon-855	4
Pixel 4a	snapdragon-730g	1
Pixel 4a 5G / Pixel 5 / Pixel 5a 5G	snapdragon-765g	9

Breakdown by source placeholder: 30 from "0", 15 from qualcomm-snapdragon.

Each repaired record gains the canonical Wikipedia device-page URL in
source_urls as the citation for the corrected soc. No other fields were
changed and no values were invented; all six target SoC records already existed
(verified: true, complete CPU/GPU/benchmark data). The assignments were
cross-checked against Wikipedia/Google and are corroborated by sibling Pixel
records in the dataset that already point at the same chips via other imports.

What was intentionally left unresolved (documented, not guessed)

The remaining ~5,600 placeholder references were not touched. The device
records carry no embedded chipset signal (no raw_chipset/chipset/raw_soc);
they hold only name/RAM/battery/display, almost all from the aitoolbuzz or
phonedb Kaggle bulk imports. Determining each real chip requires per-record web
sourcing of thousands of mostly obscure/regional devices — the exact
"repair-by-inventing-at-scale" situation prior batches (#324, #329, #330)
explicitly refused and documented instead.

A notable trap left alone on purpose: Samsung Galaxy S/Note flagships ship
different SoCs by region (e.g. SM-N960F = Exynos 9810 vs SM-N960U =
Snapdragon 845), so their placeholder-linked region variants cannot be safely
mapped without decoding each model number — a per-record sourcing task, not a
blanket mapping.

Verification

• python -m app.validate → ✅ passed.
• integrity_check.py --strict (TechEngine) → ✅ integrity gate: no hard anomalies (exit 0); hard-anomaly baseline vs. after are both 0 (no new hard
  anomalies introduced).
• Final commit refreshes the static API dump
  (python -m app.dump, TECHAPI_DATA_DIR → this worktree, fresh scratch
  DATABASE_URL): 191,819 records; the 45 Pixel smartphone detail files now
  resolve to their real Snapdragon SoC.

Closes #296