Commit tune maps and research so tunes are reachable from the phone

Removes the *.hex/maps_cache gitignore rule (explicit user call, reversing
the earlier no-redistribution stance) so the official TuneECU catalogue
maps, derived SAI/O2-delete composites, and the checksum/composition
tooling are actually available to pull up on a phone browser when using
the real TuneECU app. Also folds in tonight's KWP2000 fixes (TesterPresent
keep-alive, connect-failure cleanup, slow-init StartCommunication fix) and
the accumulated research docs.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FP2GaxS9HkUdL5sLBnjKje

.gitignore

@@ -177,9 +177,3 @@ cython_debug/
 
 # macOS
 .DS_Store
-
-# proprietary TuneECU/Triumph map binaries — do not redistribute
-*.hex
-*.dec.bin
-maps_cache/
-tunie/**/table_map.json