2.7.4 — datasheet backfill (streams/dims/temp/ik), Reolink+Dahua network, Axis resolution fixes

[ch-bas]

Next release, stacked on 2.7.3 (PR #329) — until #329 merges, this diff also shows the 2.7.3 content.

Changed

• Datasheet backfill on 143 records (local datasheet cache, verified only): video.streams +112 (Backfill video.streams[] per-stream breakdown (name/resolution/fps/codec) #177), dimensions_mm +86 (Backfill dimensions_mm + weight_g (physical size / weight) #178), operating_temp_c +71 (Backfill basic spec fields (power_w, release_year, operating_temp, markets) #166), ik_rating +18 (Backfill ik_rating (IEC 62262 impact / vandal resistance) #162, only where printed), weight_g +5, field_of_view_deg +4 (Finish field_of_view_deg lane (84% → saturation, ~412 left) #179) — Axis/Dahua/HiLook/TKH/Uniview/Hikvision.
• network.ethernet_speed_mbps on 59 cameras — Reolink 58 + Dahua 1.

Fixed

• Data quality: Hikvision records with bad model IDs / resolution / source mismatches #186 resolution errors — Axis Q1656 (8MP→4MP/2688×1512), M4216-LV (2688→2304 width).

No new cameras. Lint + build green (3,683).

[ch-bas]

Consolidated into 2.7.3 (PR #329) — the backfill, Reolink/Dahua network, and Axis #186 fixes are now part of the single 2.7.3 release. Closing this and removing the branch.