Fix 117 MediaTek, Exynos and Kirin SoC release dates

[Seungpyo1007]

Correct 117 SoC release dates with unambiguous matches on the supplied Wikipedia vendor pages. Preserve every field except release_date and source_urls, preserve slugs, and move changed-year records using git mv.

Vendor	Month/day table dates	Explicit prose dates	Quarter-start corrections	Total	Skipped
mediatek	0	0	79	79	265
samsung	0	5	30	35	128
hisilicon	0	3	0	3	59

Month/day-precise table changes: none qualified.

Explicit prose changes (8): Exynos 4212 ×2 (2011-09-29), Exynos 5250 ×2 (2011-11-30), Exynos 2200 ×1 (January 2022 represented as 2022-01-01), Kirin 9000S ×1 (2023-08-29), Kirin 9030 and 9030 Pro ×1 each (2025-11-25). These are chip announcement/introduction dates explicitly named in page prose; citation retrieval/publication dates are excluded.

Quarter-sourced changes (109): only existing YYYY-01-01 placeholders whose year differs from the table year qualify. The stored date is the first day of the stated quarter, a normalization convention rather than a claimed exact launch day. Same-year quarter-only entries and nonplaceholder dates remain untouched.

Sample	Before	After	Evidence
MediaTek Helio G99 MT6789	2025-01-01	2022-04-01	quarter: Helio G99 MT6789 MT6789G MT6789U MT6789V/CD MT8781 MT8781V/CA MT8781V/NA
MediaTek Dimensity 9000 MT6983	2023-01-01	2021-10-01	quarter: Dimensity 9000 (MT6983 MT6983Z/CZA MT8798 MT8798Z/CNZA)
Samsung Exynos 1080 5G S5E9815	2022-01-01	2020-10-01	quarter: Exynos 1080 (S5E9815)
Samsung Exynos 4 Dual 4212	2013-01-01	2011-09-29	prose: On 29 September 2011, Samsung introduced Exynos 4212
HiSilicon KIRIN9000S 4G Hi36A0 GFCV120	2023-01-01	2023-08-29	prose: On 29 August 2023, Huawei announced ... Kirin 9000S

Skips by vendor:

• mediatek: unmatched=117, coarse_or_missing_date=32, quarter_same_year_or_nonplaceholder=102, ambiguous_multiple_models=8, ambiguous_match=2, conflicting_prose_and_table_date=4.
• samsung: unmatched_or_multiple_models=62, quarter_same_year_or_nonplaceholder=51, unmatched=8, ambiguous_match=3, already_within_policy=1, ambiguous_combined_variants=3.
• hisilicon: no_precise_page_date=59.

Skip examples: MT6572 appears in multiple rows; ambiguous shared MT part numbers and combined Exynos 2400/2400e variants are excluded. Dimensity 1100/1200 have conflicting table/prose dates. Kirin models without explicit dates (including Kirin 960/970) remain untouched; cited article dates are not treated as chip launch dates.

Sources: MediaTek, Exynos, HiSilicon.

Validation: PYTHONIOENCODING=utf-8 python -m app.validate passed. Integrity checks passed for all 117 records: only release_date/source_urls changed, slugs preserved, exact change scope verified, and all 114 year-changing records moved to matching year folders.

Closes #1