Why: after material organization completes, weak models report and end the turn without offering the user a choice of formal deliverables, and even after a user picks one the model may close the turn without starting the background task.
Evidence: new tests (notice-choice chain, deliverable backstop, free-input path, invalid args, notice contract) pass; full go test ./... exit 0 (local, SELF).
Impact: new confirm_choice tool issues a HITL choice card and routes the answer into a hard delegate instruction; material notices instruct the model to report then offer choices; stop hook adds two one-shot backstops (choice not offered in material notice runs; choice made but no background delegation).
Refs: Dev task .task/feature-material-intake-flow.md I2.
Why: the dual-speed entry hint is advisory only; real runs (MiniMax, 3 attachments, no text) end with a clarifying question and zero delegation, so background cards and result backfill never start.
Evidence: new unit tests in runmgr/material_test.go and runtime/material_flow_test.go all pass; full go test ./... exit 0 (local, SELF).
Impact: attachment-carrying runs now guarantee a material-organization background task (pre-spawn on attachment-only/heavy sends, stop-hook backstop otherwise when the model did not delegate); subagent receives inline parsed text with budget plus knowledge_search guidance; content-key dedup prevents duplicate spawns (in-flight, completed, resend); model-authored delegate_task gains a materials appendix; settings runtime.materialIntake (default on) and runtime.materialIntakeChars added.
Refs: Dev task .task/feature-material-intake-flow.md I1; user ruling 2026-10-11.
agent-exec-transport
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