Refactor SIGDS docs, archive DEC log, add pipe tests
- Updated all references to AcSignalRDataSource docs to new SIGNALR_DATASOURCE/README.md location; introduced SIGDS topic and paired issues/TODO files.
- Implemented new Decision Log archival policy: last-15-active entries remain, older entries moved to year-month archive (LLMP-DEC-65, 67); updated docs-archive skill for two-rule rotation.
- Added new SIGDS architectural TODO (ACCORE-SIGDS-T-D9F2) for relocating DataSource code.
- Updated doc tables, glossaries, and conventions for SIGDS.
- Added AcBinarySerializerPipeParallelTests.cs for parallel serialization/deserialization round-trip tests.
Update ID format to use per-repo prefixes and random suffix
Migrated all issue, TODO, and decision IDs to a new 4-part format: <PREFIX>-<TOPIC>-<TYPE>-<RAND>. Added per-repo prefix declarations in copilot-instructions.md and documented conventions in REPO_PREFIXES.md. Updated all topic registries, logs, cross-references, and documentation to use the new format. Introduced MIGRATION_ID_MAPPING.md for old-to-new ID mapping. Enhanced skills and protocol audit logic to validate and enforce per-repo prefixes and topic codes at runtime. Clarified Framework-First doctrine and ensured all references are unambiguous.
Refactor docs: topic folders, TOON, XCUT, protocol sync
- Migrated all topic documentation into dedicated folders with canonical `README.md`, `ISSUES.md`, and `TODO.md` per topic (e.g., `LOGGING/`, `SIGNALR/`, `BINARY/`, `TOON/`).
- Added comprehensive TOON serializer documentation: design, format, options, attributes, inference, issues, and TODOs.
- Introduced `XCUT` folder for cross-cutting issues and TODOs, with canonical entries and topic cross-references.
- Updated all references and navigation to use new folder-based doc paths; fixed links and clarified doc structure.
- Enhanced AI agent protocol: enforce session skill preloading, `[LOADED_DOCS: ...]` short-name prefix, and mandatory `docs-check` skill for doc/code sync.
- Updated `.csproj` to include all `README.md` files for IDE visibility.
- Improved and clarified SignalR, grid, and project-level documentation.
- Minor code/test tweaks and doc content corrections for consistency.
Loretta