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phases/6-cli-runtime-resume/step4.md

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+# Step 4: model-cache-offline
+
+## Read First
+- /AGENTS.md
+- /PLAN.md
+- /PROGRESS.md
+- /docs/HARNESS.md
+- /docs/IMPLEMENTATION_PLAN.md
+- /docs/TOOLCHAIN.md
+- /docs/ARCHITECTURE.md
+- /phases/6-cli-runtime-resume/step3.md
+
+## Task
+Document and wire model cache/offline behavior for Marker, Nougat, and Hugging Face cache paths.
+
+Add CLI/runtime hooks for environment variables or explicit cache paths without downloading models during tests.
+
+## Sprint Contract
+- Done means: users can see how to pre-download models and run offline, and runtime cache paths are configurable.
+- Hard thresholds: no test performs network download; docs include Windows commands; cache path policy matches Phase 1.
+- Files owned: `src/pdftomd/runtime.py`, `README.md`, `docs/TOOLCHAIN.md`, tests, `PROGRESS.md`, phase index.
+- Dependencies: Device/runtime policy and cache contracts.
+
+## Acceptance Criteria
+```powershell
+python scripts\validate_workspace.py
+.\venv\python.exe -m pytest tests
+```
+
+## Verification
+1. Run the acceptance commands.
+2. Confirm offline instructions are clear and do not imply bundled weights.
+3. Update `PROGRESS.md` and this phase index.
+
+## Do Not
+- Do not download model weights as part of tests.
+- Do not commit model caches.
+- Do not make online access mandatory for already-cached models.