Merged after conflict resolution onto the post-#10961 tip (verified no clobber of today's plaintext-wins work — the resolver functions were appended and the chatCore call-site swapped; a first --theirs attempt was caught reverting #10961 and redone hunk-by-hunk). resolveIncompatibleReasoningAction now defaults single-target incompatible reasoning to drop while combos keep their explicit strategy, with the x-omniroute-reasoning-fallback header override. 21/21 reasoning suites green, typecheck clean. Fixes#10959. Thank you @adevwithpurpose!
Validated on the combined batch board + this branch: 231/231 across chatcore-translation-paths, reasoning-cache, strip-reasoning-blobs, and both Responses translator suites. Pre-merge: propagated the #11110/#11129 summary:[] defaults into five assertions here (each commented with its PR) — without it this branch red against the tip, and as a bonus the merge drains the 4 reasoning reds that were live on the tip from those merges. Plaintext now wins over a coexisting opaque companion; opaque-only drops cleanly for plaintext targets; combos keep explicit Skip. Fixes#10949 and #10959. Thank you @jackjinke!
Validated on the combined batch board over release/v3.8.50 tip d91238b7: static gates clean, typecheck:core clean, focused tests green.
Defaults summary and strips malformed ids on kept Responses input items — both 400s observed against live muse-spark traffic; the flipped legacy assertion is documented contract propagation. Thank you @maxmad64bis!
