chore: keep reference photography local and out of the repository

Reference images are development-only material: licensing is not a gate for
local private use, so they are simply never committed. Art/reference/ is now
gitignored; the licensed status of anything shipped is still recorded in
THIRD_PARTY_NOTICES.md.

Adds Tools/commons_fetch.py, which fetches Wikimedia Commons imagery by search
or exact title and writes a provenance sidecar, plus Docs/reference-notes-hollywood.md
recording what each local set is evidence for.

ROADMAP.md

@@ -36,8 +36,8 @@ Status detail in [Docs/setup.md](Docs/setup.md); workstation audit in [Docs/envi
 ### Asset production
 
 - [ ] Establish a consistent scale test, named export presets, and repeatable import settings.
-- [-] Collect licensed reference photography for manual façade work.
-- [ ] Download licensed reference photography for the two north-side buildings inside the 50 m buffer — TCL Chinese Theatre (OSM way 424105908, 6925 Hollywood Blvd) and Madame Tussaud's (way 424105889, 6933 Hollywood Blvd). No photograph of either exists in the current set. Keep the licence/provenance sidecar pattern from `Art/reference/hollywood/`, and do not source them from an unlicensed image search. See `Docs/data-inventory.md` for the tooling available.
+- [-] Collect reference photography for manual façade work. Local only, never committed: `Art/reference/` is gitignored, and what each set establishes is written up in `Docs/reference-notes-hollywood.md`. Still missing: the east retail neighbours 6806–6822, a night frame of the hero façade, and a sidewalk-level view of the hero entry.
+- [x] Download reference photography for the two north-side buildings inside the 50 m buffer — TCL Chinese Theatre (OSM way 424105908, 6925 Hollywood Blvd) and Madame Tussaud's (way 424105889, 6933 Hollywood Blvd). Done 2026-11-06 with `Tools/commons_fetch.py` against the Wikimedia Commons API: eleven frames in the local `Art/reference/north-chinese/` and `Art/reference/north-tussauds/`, provenance in each `sidecar.json`, nothing committed.
 - [ ] Model hero façade for the El Capitan Entertainment Centre site.
 - [ ] Model surrounding block frontage.
 - [ ] Model simplified background buildings directly across Hollywood Boulevard.