fix(core-domain-api): volatile async state, escape quoted SQL values, fix XLXS typo, align PinTable hashCode

[HandSonic]

Problem

Four defects in domain-api:

1. ExportFileSuffixEnum typo: XLXS(".xlxs") — exported Excel files got the misspelled .xlxs suffix.
2. Unescaped SQL literals: DataTypeEnum.getValue wrapped values in single quotes directly ("'" + value + "'") for BOOLEAN-fallback, DATETIME, CONTENT, STRUCT, DOCUMENT, ARRAY, OBJECT, REFERENCE, ROWID, ANY, and UNKNOWN — any value containing ', ", or \ produced broken or injectable SQL.
3. AsyncContext visibility: finish, progress, info, and error are written by a worker thread and polled from another thread, but were not volatile — the poller could spin forever on a stale finish=false.
4. PinTable equals/hashCode contract: PinTable overrides equals but not hashCode, so equal instances landed in different hash buckets and HashMap/HashSet/contains behaved incorrectly.

Fix

• Rename enum constant to XLSX(".xlsx")
• Route all those branches through getStringValue, which escapes \, ', and " before quoting
• Mark the four AsyncContext fields volatile
• Add PinTable.hashCode over the same fields used by equals

Tests

New ExportFileSuffixEnumTest, DataTypeEnumTest, AsyncContextTest, PinTableTest (junit-jupiter added to module test scope). mvn test on chat2db-community-domain-api: 11/11 pass.

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Verified on fork HandSonic#22 (meaningful CI checks green; dependency-review/project-sync jobs are fork-permission noise). Regression tests pass; adversarial review cleared.