docs: drop two retired CCTV client flags from the env template (#503)

Supersedes #283 by @dajiaohuang, ported onto the current component layout with fixes from review.

Verified before merge: format, package boundaries, unit suite, build, and the browser tracking suite; a browser harness for the change where one applies; adversarial review applied.

Co-authored-by: dajiaohuang <[email protected]>

.env.example

@@ -171,5 +171,3 @@ AISSTREAM_API_KEY=
 # CCTV_MAX_SOURCES=4000                                # catalog-wide ceiling, shared round-robin across packs
 # CCTV_PREFER_AUSTIN=1                                 # prioritize Austin cameras in the registry
 # CCTV_FORCE_AUSTIN=                                   # force live default sources when a source-pack JSON is configured
-# CCTV_AUTO_CALIBRATE=1                                # auto-calibrate camera projection (client flag)
-# CCTV_DRAPE_MESH=1                                    # drape frames onto 3D geometry (client flag)

CHANGELOG.md

@@ -328,6 +328,9 @@ of current runtime behavior, see [`docs/CURRENT-STATE.md`](docs/CURRENT-STATE.md
   whoever adds the next destination; it passes on the current entries and makes
   no claim about how well any destination is framed. Contributed by daikaginza
   (#168).
+- Drop `CCTV_AUTO_CALIBRATE` and `CCTV_DRAPE_MESH` from `.env.example`. Nothing
+  reads either name; the features they once switched no longer exist, so setting
+  them did nothing. Contributed by dajiaohuang (#283).
 
 - Extract application lifecycle and viewer exports. Split standalone startup into
   scene setup, controls, layer registration, tools and loading UI. Startup failure