[Idea] Graph-build preflight validation + progress watchdog

[sfc-gh-obielov]

Triage note (2026-04-23): This ticket absorbs #55 (document memory / JVM sizing per region and switch large extracts to MMAP). Sizing guidance from #55 is exactly the input a preflight validator needs to warn users before a 3-day hang on a continental extract. One implementation satisfies both.

Consolidated scope:

1. Preflight validator (original scope): pre-check borders/countries flags against PBF size, required RAM, required disk; refuse or warn with actionable output.
2. Progress watchdog (original scope): emit a heartbeat during long graph builds; surface stalls.
3. Sizing table (absorbed from [Idea] Document memory / JVM sizing per region and switch large extracts to MMAP #55): ship a ## Sizing section in build-routing-solution/SKILL.md mapping city → PBF size → RAM → -Xmx recommendation, plus graphs_data_access: MMAP guidance for continental extracts.
4. Deploy-time validation (absorbed from [Idea] Document memory / JVM sizing per region and switch large extracts to MMAP #55): validate configured SPCS resources vs. selected PBF before starting the graph build — fail fast with a clear error if under-provisioned.

Close #55 as absorbed-by this ticket.

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Context

Users report graph builds hanging for 3+ days with no error when borders are enabled. Forum's most-viewed config thread (Users report graph builds hanging for 3+ days with no error when borders are enabled. Forum's most-viewed config thread (Users report graph builds hanging for 3+ days with no error when borders are enabled. Forum's most-viewed config thread (Users report graph builds hanging for 3+ days with no error when borders are enabled. Forum's most-viewed config thread ([Users report graph builds hanging for 3+ days with no error](https://ask.openrouteservice.org/t/ors-stuck-when-how-to-use-the-docker-config-file-ors-config-yml/

[sfc-gh-obielov]

Addressed in PR #120 (commit e90f211). Absorbs #55.

Implementation:

• New VALIDATE_REGION_PREFLIGHT(region) procedure in 03_region_management.sql. Estimates PBF / graph size from bbox area, warns when configured compute pool is undersized for the selected preset. Pure advisory — never mutates state.
• Build-progress endpoint scrapes ORS log markers (_OSM_DONE, _LM_DONE, _CH_DONE, _BUILD_OK) and surfaces phase + LM landmark N/M progress + log tail.
• BuildSummaryCard (commit 1fb5c2a) renders live phase + ETA + log tail in the React Region Builder UI.
• ## Sizing section added to build-routing-solution/SKILL.md mapping city → PBF size → RAM → -Xmx recommendation, plus graphs_data_access: MMAP guidance for continental extracts.

Audit follow-up applied:

• Added ALTER SESSION SET query_tag at top of 03_region_management.sql.

[sfc-gh-obielov]

Addressed in PR #120 (commit e90f211). Absorbs #55.

Implementation:

• New VALIDATE_REGION_PREFLIGHT(region) procedure in 03_region_management.sql. Estimates PBF / graph size from bbox area, warns when configured compute pool is undersized for the selected preset. Pure advisory — never mutates state.
• Build-progress endpoint scrapes ORS log markers (_OSM_DONE, _LM_DONE, _CH_DONE, _BUILD_OK) and surfaces phase + LM landmark N/M progress + log tail.
• BuildSummaryCard (commit 1fb5c2a) renders live phase + ETA + log tail in the React Region Builder UI.
• ## Sizing section added to build-routing-solution/SKILL.md mapping city → PBF size → RAM → -Xmx recommendation, plus graphs_data_access: MMAP guidance for continental extracts.

Audit follow-up applied:

• Added ALTER SESSION SET query_tag at top of 03_region_management.sql.