Cargo: codec 3ec70a2, kernel e710727, graph 338a973

The codec keeps dynamic-block, associative and material records intact on
DWG save (strict readers rejected re-saved drawings at BLOCKSCALEACTION,
associative action bodies and MATERIAL records). A checker material
texture no longer rewrites the native map source, so a map with a
procedural texture counts as content whatever its source says.

Valuable parts of #1671 (with opencadcodec#100): measured on 235 sample
drawings re-saved after an edit, a strict reader now rejects 4 instead
of 7; the remaining 4 are R14/R2000 tables, which the PR codec also
fails.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/opencad-python/Cargo.lock

@@ -1264,7 +1264,7 @@ dependencies = [
 [[package]]
 name = "opencadcodec"
 version = "0.6.0"
-source = "git+https://github.com/HakanSeven12/opencadcodec.git?rev=8189f83#8189f833574c544fc57a1d773591014c3a5907c9"
+source = "git+https://github.com/HakanSeven12/opencadcodec.git?rev=3ec70a2#3ec70a2a0134f60a9f3036f1974fea86ad96e439"
 dependencies = [
  "anyhow",
  "bitflags",