CMMS fork: re-vendor all runtime deps locally, strip analytics

Upstream loads zip.js, OpenCV.js, WireBender (JS+WASM) and Google Fonts
from CDNs at runtime, and includes a Google Tag / gtag.js snippet. The
CMMS deployment forbids external requests. Changes:

- docs/vendor/ — local copies of opencv.js (Apache-2.0), zip.min.js
  (BSD-3-Clause), WireBender.{js,wasm} (AGPL-3.0/commercial, source at
  github.com/dev-lab/WireBender), and the three Google fonts (OFL, latin
  subset). SOURCE.txt records provenance.
- studio.html / schema.html — zip.js + opencv.js + fonts @import point at
  docs/vendor/.
- inspect-traces.js / schema/layout.js — WireBender import() + locateFile
  point at docs/vendor/wirebender/.
- every *.html — Google Tag / gtag.js snippet removed.

No behaviour change; kicad-symbols zip was already bundled + local.
CMMS embedding hooks (window.PCBRETRACE_CONFIG, save-back, AI bridge)
land in a later commit.

docs/vendor/SOURCE.txt

@@ -0,0 +1,36 @@
+Third-party runtime dependencies, vendored locally for the CMMS fork
+==================================================================
+
+Upstream pcb-retrace loads these from CDNs at runtime. The CMMS deployment
+forbids external requests (CSP + offline-capable), so they are copied here and
+the references in ../studio.html, ../schema.html, ../inspect-traces.js and
+../schema/layout.js are rewritten to these local paths. Fetched 2026-09-03.
+
+opencv.js
+  https://docs.opencv.org/4.x/opencv.js  (OpenCV 4.x prebuilt, single-file,
+  wasm embedded as a base64 data URI — no separate .wasm)
+  License: Apache-2.0. Used by cv-core.js for ORB feature matching / photo
+  alignment only.
+
+zip.min.js
+  https://cdn.jsdelivr.net/npm/@zip.js/zip.js@2.8.26/dist/zip.min.js
+  License: BSD-3-Clause (Gildas Lormeau). Project-ZIP + kicad-symbols-zip
+  read/write.
+
+wirebender/WireBender.js + WireBender.wasm
+  https://dev-lab.github.io/WireBender/latest/{WireBender.js,WireBender.wasm}
+  License: dual AGPL-3.0-only OR commercial (Taras Greben). Corresponding
+  source: https://github.com/dev-lab/WireBender  (not modified here — the
+  published binary is redistributed as-is alongside this AGPL fork).
+  Cosmetic net-trace routing for the Inspect view + Schema ReTrace layout.
+  ES module (uses import.meta.url); the .wasm is resolved by emscripten's
+  default locateFile relative to the module, or via the explicit URL() in
+  schema/layout.js.
+
+fonts/  (Rajdhani v17, Share Tech Mono v16, Space Mono v17 — latin subset only)
+  https://fonts.googleapis.com/css2?family=Share+Tech+Mono&family=Rajdhani:wght@400;500;600;700&family=Space+Mono:wght@400;700
+  License: SIL Open Font License 1.1. Used by schema.html only. fonts.css
+  replaces the external @import.
+
+../assets/kicad-symbols-master.zip is bundled by upstream itself (KiCad symbol
+libraries, CC-BY-SA-4.0 + KiCad library exception) — not added here.