chore(places): vendor MapLibre GL JS + pmtiles.js for the photo map

Vendored for the self-hosted Places map (Approach A: client-side PMTiles
decoding, basemap served as a static file via the existing Range-capable
ServeDir):
- maplibre-gl 5.24.0 (BSD-3) + its CSS
- pmtiles 4.4.1

Also adds static/basemaps/ with a .gitignore (*.pmtiles is operator-provided,
never committed) and a README explaining how to drop in a basemap.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JW6ghFMDtnRYuYNzZhb47M

static/basemaps/.gitignore

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+# The vector basemap is large (tens of MB) and operator-provided — never
+# commit it to the repo. Drop a Protomaps `.pmtiles` here as `basemap.pmtiles`
+# and the existing static file server (tower-http ServeDir, Range-capable)
+# will serve it to the Places map. See README.md.
+*.pmtiles

static/basemaps/README.md

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+# Places basemap (optional)
+
+The **Places** photo map renders your geotagged photos as clusters. It works
+out of the box **without** a basemap (clusters on a plain background). To get a
+real street/terrain backdrop, drop a self-hosted vector basemap here — no
+third-party tile API, fully offline.
+
+## How it works (Approach "A")
+
+OxiCloud already serves `static/` through `tower-http`'s `ServeDir`, which
+honours **HTTP Range** requests. A [PMTiles](https://docs.protomaps.com/pmtiles/)
+basemap is a *single file* read directly by the browser via Range — so the
+basemap is just a static file the app already knows how to serve. No extra
+backend, no tile server, no API keys.
+
+## Enabling it
+
+1. Get a Protomaps `.pmtiles` basemap (vector, ODbL OpenStreetMap data):
+   - Whole planet z0–15 (~120 GB) or a smaller global `z0-6` (~60 MB), or
+   - A **regional extract** (recommended — only the area you need, a few MB):
+     ```sh
+     # one-time, downloads only your bounding box from the remote planet
+     pmtiles extract https://build.protomaps.com/<DATE>.pmtiles basemap.pmtiles \
+       --bbox=<west>,<south>,<east>,<north>
+     ```
+     See https://docs.protomaps.com/basemaps/downloads
+2. Place it here as **`static/basemaps/basemap.pmtiles`** (this path is
+   git-ignored on purpose — see `.gitignore`).
+3. Reload the Places view. The map will pick it up automatically.
+
+The bundled style is **label-light** (water / land / roads / buildings, no
+text) so it needs no glyph/sprite assets. Attribution “© OpenStreetMap”
+(ODbL) is shown automatically when a basemap is present.

static/js/vendors/VERSIONS.txt

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+maplibre-gl 5.24.0
+pmtiles 4.4.1