feat(examples): package ABI course deep projects

[svonava]

Part of sie-internal#1963.

Complements #213's minimal managed-cloud smoke with the remaining deep-example course packaging. It intentionally does not claim managed US-production readiness before the parallel model-catalog work is frozen and measured.

What changed

• Select retrieval-ablation as the third project from code evidence: it has qrels plus NDCG/Recall evaluation and isolates reranking as one controlled change. Use document-ocr as the bounded fixture/OCR stage of vision-doc-rag rather than a separate retrieval project.
• Add examples/abi-course-deep with a machine-readable three-project manifest, explicit catalog/model-revision gates, expected output contracts, change/measurement prompts, and intentionally null credit/budget fields.
• Add a 12-document/six-query synthetic retrieval fixture and a dependency-free offline contract plus live dense-versus-rerank runner. Live mode requires explicit catalog-frozen model IDs and reads the key only from SIE_API_KEY.
• Add a deterministic vision corpus preparer that SHA-256 verifies and copies exactly three existing Apache-2.0 synthetic document images; no PDF or dataset download is needed.
• Add ten fast offline contract tests for sample bounds, qrels, fixture hashes, output shapes, unresolved catalog/budget gates, deterministic preparation, and credential-shaped literals.
• Commit frozen Python 3.12 locks for the course pack and contract-review example; the latter previously ignored uv.lock despite being the principal student example.
• Link all three source examples to the bounded course path and mark their current model IDs as candidates pending catalog freeze and live validation.

Safety and release gates

• No real API key is logged, persisted, or passed on the command line.
• No AWS, Modal, managed SIE, or external dataset calls were made.
• Managed model IDs/revisions, cold/warm latency, request IDs, usage, settled credits, and per-student budget remain explicit null/live_measurement_required gates until #1943 and the US-production exercise are complete.

Validation

• uv sync --project examples/abi-course-deep --frozen
• uv run --project examples/abi-course-deep --frozen python -m unittest discover -s examples/abi-course-deep/tests (10 passed)
• uv run --project examples/abi-course-deep --frozen ruff check examples/abi-course-deep
• uv run --project examples/abi-course-deep --frozen ruff format --check examples/abi-course-deep
• uv sync --project examples/contract-review-agent --frozen
• uv run --project examples/contract-review-agent --frozen make-sample (3 contracts, one scan, 12 obligations)
• uv run --project examples/contract-review-agent --frozen review --list
• Python compile checks for the course pack, contract-review, and vision-doc-rag scripts
• git diff --check

[svonava]

@coderabbitai review

[svonava]

Superseded by #213. We are improving the canonical quickstart, retrieval-ablation, vision-doc-rag, and contract-review examples directly instead of maintaining an ABI-course-specific package or manifest. The useful bounded/offline paths were reimplemented and validated in those canonical examples; this PR will not be merged.