Add Dragon-backed XPOIS image-pair batches

[tpn]

This PR adds fit-batch-dragon for XPOIS image-pair fitting. The coordinator reads a manifest, assigns complete fits to GPU workers with explicit device placement, balances work by input size, and saves per-item results and a run summary. Each image-pair fit runs on one GPU.

This PR distinguishes valid failed-item records and record-write failures from inconsistent shard reports. Follow-up #10 adds MPI execution, preserves worker failure records when placement validation fails, and extends batch failure and provenance checks.

The command requires DragonHPC (dragonhpc, imported as dragon) in the same Python environment as cuPhoton on every participating node. Installing cuPhoton alone does not install DragonHPC. The documentation covers installing the released runtime and launching a batch, and the third-party notices record this dependency.

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• docs/components/xpois.md
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📝 Walkthrough

Walkthrough

The change adds manifest-driven XPOIS image-pair fitting across DragonHPC GPU workers. It adds validated work contracts, input checks, worker orchestration, result auditing, CLI integration, timing data, documentation, and tests.

Changes

XPOIS Dragon batch fitting

Layer / File(s)	Summary
Bulk work contracts and persistence src/cuphoton/core/bulk.py, tests/core/test_bulk.py	Added validated work items and placements, deterministic byte-balanced partitioning, terminal-record audits, atomic JSON persistence, and utility validation.
Manifest-driven batch processing src/cuphoton/xpois/batch.py, src/cuphoton/xpois/workflows.py, tests/xpois/test_batch.py	Added strict manifest loading, input identity checks, fit-option validation, shape preflight, per-item execution, and workflow timing fields.
Dragon placement and lifecycle orchestration src/cuphoton/xpois/dragon.py, tests/xpois/test_dragon.py	Added GPU discovery, worker placement, shard execution, provenance checks, result audits, lifecycle handling, timing aggregation, and failure reporting.
Command integration and runtime documentation src/cuphoton/xpois/commands.py, examples/xpois/dragon_batch.py, tests/xpois/test_cli.py, tests/core/test_cli_contract.py, docs/components/xpois.md, THIRD_PARTY_NOTICES.md	Added the fit-batch-dragon command and wrapper. Updated CLI contracts and documented DragonHPC requirements, manifests, execution rules, and limitations.

Priority: ⬆️ High

Unblocks: 8 PRs

Merge Risk: ⚪ Minimal · up to 72ddd

The batch command and distributed workflow are ready to merge after normal checks.

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✅ Passed checks (2 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[melo-gonzo]

LGTM with nits. The failure-path evidence fixes that already landed internally (record written before the placement-mismatch raise, status/failed_count no longer feeding the shard mismatch set) arrive in #10. Worth stating that dependency in this PR body so a reader of the 0.1.3 history knows #8 alone is not the hardened version.

[tpn]

Preserved your changes and added the count reconciliation in 8d022a49. A real worker with an injected disk-full error reports that item as a failed write even when no terminal record exists; a directory-sync failure can also leave the record visible. Both cases now remain failed runs with write_failed_shards, without a false terminal-count mismatch. Malformed, unknown and duplicate error identities still count as inconsistent evidence. All 104 focused tests and lint passed.

The honest per-item failure checks and unreachable auto branch are already handled by your commit. The dependent MPI PR keeps those changes and its launcher and timeout behavior.

The automatic-mask boundary checks are fixed in daba44db: enabled masks require a stamp size of at least 3, and peak percentiles must be strictly between 0 and 100. The three failing boundary regressions now pass; disabled masks still accept a one-pixel stamp. The full CPU suite passed (1,081 tests), and the fix has been carried into the dependent branches.

[melo-gonzo]

Re-approving after the rebase. 8d022a4 tightens the record_write_errors contract (item_id in shard, type and message strings, no duplicates) and counts write failures as failed items, which closes the remaining half of the issue #4 analog. Looks right.

[melo-gonzo]

Re-approving after the second rebase onto main with #19: the only content change is the CLI-contract count assertion (xscan 166 -> 167, totals 766/788 -> 767/789); d2d483d and f10a4d9 are unchanged.

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Inline comments:
In `@src/cuphoton/xpois/batch.py`:
- Around line 334-342: Update the auto_peak_percentile validation in
BatchFitOptions to require a finite value strictly greater than 0 and less than
100, so invalid boundaries are rejected before workers launch. Revise the
ValueError message to state that the value must be strictly between 0 and 100.
- Around line 322-327: Update the BatchFitOptions validation around
auto_stamp_size so that, when auto_stamp_mask is enabled, values below 3 are
rejected at the option boundary with a clear ValueError; preserve the existing
positive odd-integer validation otherwise.

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📥 Commits

Reviewing files that changed from the base of the PR and between 2c15282 and f10a4d9.

📒 Files selected for processing (13)

• THIRD_PARTY_NOTICES.md
• docs/components/xpois.md
• examples/xpois/dragon_batch.py
• src/cuphoton/core/bulk.py
• src/cuphoton/xpois/batch.py
• src/cuphoton/xpois/commands.py
• src/cuphoton/xpois/dragon.py
• src/cuphoton/xpois/workflows.py
• tests/core/test_bulk.py
• tests/core/test_cli_contract.py
• tests/xpois/test_batch.py
• tests/xpois/test_cli.py
• tests/xpois/test_dragon.py

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[tpn]

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[melo-gonzo]

Re-approving after the rebase. 7cf22b9 tightens the automatic-mask option validation before workers start (odd stamp size of at least 3 when masking, percentile strictly inside 0 to 100), and the only other deltas are doc anchors and the CLI count assertion.

[melo-gonzo]

Re-approving after the rebase onto e6e21cc. The four commits are patch-identical to the ones approved earlier (72ddd0e, 319b0b9, ecbdc4c); the base commit differs only in the CLI-contract count assertions from the merges of #9, #36, and #38. CI passes.