com_r35157_nenjim-hubd-impl_ref/openspec/changes/archive/2026-08-06-60-add-assetaz-ticker-service/tasks.md

1. AssetAZ Ticker API

• 1.1 Add stable EVE and USDC currency ValueTypes and the well-known EVE_USDC TradingPair.
• 1.2 Add immutable PriceObservation with a timestamp and AssetPrice in the ticker API package.
• 1.3 Extend TickerService with start() and PriceObservation getLatestPrice(TradingPair), using clear exceptions for unsupported/inactive pairs and enabled pairs without a persisted observation.

2. File-Backed Reference Implementation

• 2.1 Implement explicit activation from the existing data/assetaz/ticker/EVE_USDC.prices file without creating a missing file or directory.
• 2.2 Implement the strict UTC uuuuMMddHHmmssSSS'Z':<price> format and line-by-line history parsing with empty-line and full-line/inline comment support.
• 2.3 Report malformed data with filename, one-based physical line number, and identifying invalid content, and restore the valid observation with the greatest observedAt timestamp as latest.
• 2.4 Implement thread-safe append-and-FileChannel.force(true) behavior that persists every generated observation, never exposes an unpersisted observation, preserves the prior latest observation on persistence failure, and replaces latest after successful persistence only when the new observedAt timestamp is later.
• 2.5 Generate the hardcoded 14.85 startup observation immediately and use fixed-delay scheduling only for the enabled pair so each subsequent attempt begins one minute after the preceding attempt completes.

3. Temporary Autorun Wiring

• 3.1 Start TickerServiceImpl from NenjimHub's current direct autorun mechanism without wiring it to any consumer.

4. Verification

• 4.1 Compile the project and manually verify missing, empty/comment-only, out-of-order valid, future-dated, malformed, and unwritable history-file behavior, required exception cases, timestamp/price formatting, fixed-delay timing without catch-up attempts, persist-before-publish ordering, and greatest-observedAt latest selection without adding automated tests.