chore(v1.3.0): build major-triangle tick caches and purge source artifacts

[dmidlo]

Build the local ASCII tick Polars cache set for the new major-triangles instrument group and purge transient source artifacts so only internal .data caches remain.\n\nScope:\n- Use the new major-triangles group from #261.\n- Build missing tick-data cache entries with cache-only mode.\n- Remove ZIP/CSV/XLS/XLSX source artifacts after cache materialization.\n- Monitor disk pressure and runtime/workflow state during the operation.\n- Do not publish or commit generated cache artifacts.

Post-#416 triangle-cache guardrails

The EURUSD triangle shakedown in #416 should guide any resumed major-triangle cache work.

Observed local triangle state from #416:

pair	months	first	last	rows	cache size	raw caches	enriched caches
eurgbp	292	200203	202606	288,931,679	7.535 GiB	292	0
eurusd	314	200005	202606	342,544,140	8.934 GiB	314	0
gbpusd	314	200005	202606	363,378,721	9.477 GiB	314	0

Regression guardrails:

• Treat existing triangle .data caches as legacy raw until enriched on read or migrated.
• Any Influx/report/training projection from those caches must include enriched training fields, not market-only lines.
• Triangle runs should report unequal ranges explicitly; common EURUSD/GBPUSD/EURGBP coverage starts at 200203 because EURGBP is the limiting leg.
• Continue to avoid committing generated cache artifacts.

[dmidlo]

Operational cache build update:\n\n- Ran cache-only tick build for one missing major-triangle instrument: audcad.\n- audcad now has 226 Polars .data cache files, about 8.7 GiB.\n- Source artifacts were purged after the run; current ZIP/CSV/XLS/XLSX count is 0.\n- Major-triangles cache coverage is now 8/28 instruments. Missing: audchf, audjpy, audnzd, cadchf, cadjpy, chfjpy, euraud, eurcad, eurchf, eurgbp, eurjpy, eurnzd, gbpaud, gbpcad, gbpchf, gbpjpy, gbpnzd, nzdcad, nzdchf, nzdjpy.\n- Local free disk is about 44 GiB after audcad. One full symbol consumed about 8.7 GiB, so completing the remaining 20 symbols is not safe on this volume without freeing substantial space or moving the cache root.\n- Temporal runtime was stopped after the run.

[dmidlo]

Correction after implementation audit:\n\n- The earlier operational cache comment was based on the workspace APFS volume reporting about 44-48 GiB free, not on the intended domain definition of the group.\n- The major-triangles implementation has now been tightened under #261 so relationships mirror the data-quality rule: (direct, numerator, denominator) with numerator / denominator ~= direct.\n- The group still resolves to 28 downloadable instruments and 56 oriented relationships; HistData downloads instruments, not relationship objects.\n- Current local cache coverage remains 8/28 symbols after audcad; source artifacts remain 0.\n- I am not running the remaining 20-symbol cache build into this data directory until we either point --data-directory at a larger cache root or confirm that this APFS volume can safely absorb the remaining cache growth.

[dmidlo]

Operational cache build update:\n\n- Ran full cache-only tick build for --pair-groups major-triangles until disk safety cutoff.\n- Stopped/cancelled workflow histdatacom-run-6f3bd36417894a78b2657e90da56dfc9 when free space crossed below 8 GiB during monitoring.\n- Temporal runtime is stopped; no server/worker processes remain.\n- Cleaned transient sources after stop: deleted 124 ZIP files, about 610 MB. Current ZIP/CSV/XLS/XLSX count is 0.\n- Current major-triangles cache coverage: 15/28 instruments, 3,859 cache files, about 122.1 GB.\n- Still missing: eurcad, eurchf, eurgbp, eurjpy, eurnzd, gbpaud, gbpcad, gbpchf, gbpjpy, gbpnzd, nzdcad, nzdchf, nzdjpy.\n- Current local free disk is about 8.2 GiB, so the remaining build should wait for more space or a larger --data-directory.

[dmidlo]

Operational cache build update:\n\n- Resumed the same cache-only run: python -m histdatacom -C --pair-groups major-triangles -f ascii -t tick-data-quotes --data-directory data -v.\n- Existing .data caches were reused by the cache path; the run started from 15/28 cached and advanced to 18/28.\n- Stopped/cancelled workflow histdatacom-run-3e8a91a3f62c4a09a5807e326b1acbdf when free space crossed below the 8 GiB safety floor.\n- Temporal runtime is stopped; no server/worker processes remain.\n- Cleaned transient sources after stop: deleted 62 ZIP files, about 222 MB. Current ZIP/CSV/XLS/XLSX count is 0.\n- Current major-triangles cache coverage: 18/28 instruments, 4,676 cache files, about 153.0 GB.\n- Still missing: eurjpy, eurnzd, gbpaud, gbpcad, gbpchf, gbpjpy, gbpnzd, nzdcad, nzdchf, nzdjpy.\n- Current local free disk is about 6.5 GiB.

[dmidlo]

Cache sizing update:\n\n- Source artifact cleanup found nothing to delete: current ZIP/CSV/XLS/XLSX count is 0.\n- Repo-local build/test artifacts are negligible compared with data: dist/build/.pytest_cache/.mypy_cache/.ruff_cache are under ~20 MB total.\n- Major-triangles symbols with any cache: 18/28, total cache size about 142.5 GiB by filesystem walk.\n- Average across those 18 cached symbols: about 7.92 GiB.\n- Better planning average excluding partial eurgbp (38 cache files, ~0.20 GiB): about 8.37 GiB per completed/near-complete instrument.\n- Current free disk after cleanup check is about 4.9 GiB, so continuing on this volume is not safe without freeing substantial additional space or using a different --data-directory.

[dmidlo]

Safety-stopped the major-triangles cache build after disk free space crossed below the guardrail.\n\nLatest local state:\n- Runtime stopped; no lingering temporal/histdatacom processes observed.\n- Source artifacts cleaned: 0 ZIP/CSV/XLS/XLSX files remain under data.\n- Coverage is now 20/28 major-triangle symbols cached. Newly completed in this run: eurjpy and eurnzd.\n- Remaining missing symbols: gbpaud, gbpcad, gbpchf, gbpjpy, gbpnzd, nzdcad, nzdchf, nzdjpy.\n- Completed cache total: 172.34 GiB across 20 symbols; average 8.62 GiB/symbol; observed range 5.65-14.46 GiB.\n- Free disk after cleanup: ~5.0 GiB, so the run should not be resumed until more disk is available or caches are moved/pruned.\n\nNo clearable source artifacts remain; remaining space pressure is the internal .data cache itself.

[dmidlo]

Permanently blocked: external storage prerequisite

This issue must remain open but is excluded from work elections until it is explicitly unblocked.

The major-triangle cache build cannot resume on the repository volume. The operator has an iSCSI SAN that must be attached first. Resumption requires all of the following:

• attach and mount the iSCSI SAN;
• verify usable capacity and a safe free-space floor;
• validate filesystem behavior and sustained read/write operation for the cache workload;
• select/configure the SAN-backed --data-directory;
• confirm that existing caches will be moved, reused, or rebuilt deliberately.

Do not resume the 28-symbol cache build on the current volume and do not elect this issue again unless the blocker is explicitly removed.