Summary
This PR continues the OpenViking direction from TinyAGI#127 and remains stacked on #1 and #2 lineage (TinyAGI#127 -> #1 -> #2).

It integrates TinyClaw with OpenViking native Session + Search flow while preserving legacy markdown fallback, and pluginizes OpenViking context handling so core queue processing is no longer OpenViking-hardcoded.

What this PR adds

1. OpenViking context is now truly pluginized
   OpenViking context/session/search/writeback logic is moved behind the TinyClaw plugin system.
   Core queue-processor now calls generic plugin lifecycle hooks:
   onSessionReset
   beforeModel
   afterModel
   onSessionEnd
   plus onStartup / onHealth
   When OpenViking plugin is disabled, TinyClaw runs normally without OpenViking calls.
2. Native OpenViking session lifecycle as primary write path
   Create/reuse session via stable mapping:
   (channel, senderId, agentId) -> openviking_session_id
   Write user/assistant messages to native session.
   Commit on reset.
   Keep fallback writeback path explicit and observable.
3. Native OpenViking search as primary prefetch path
   Prefer typed retrieval from memory/resource/skill.
   Memory-first composition for injected context.
   Structured short snippets for prompt injection (instead of large raw turn blocks).
4. Compatibility fallback retained
   Legacy markdown path (active.md / *.md) is still supported.
   Fallback reasons are explicitly logged.
   Legacy path is managed inside plugin logic (not core flow branches).
5. Better observability
   Native session write/commit success/failure logs.
   Retrieval hit distribution logging (memory/resource/skill).
   Explicit fallback reason + diagnostics logging.
   Native prefetch dump for debugging:
   prefetch_dump_native_latest.txt
6. Setup/runtime compatibility preserved
   Existing OpenViking feature flags remain compatible.
   Existing user-visible context injection format is preserved.
   Telegram/WhatsApp/Discord message pipeline behavior remains unchanged.
   Key files touched
   queue-processor.ts
   plugins.ts
   index.ts
   prefetch.ts
   session-map.ts
   openviking-prefetch.ts (compat re-export)
   openviking-session-map.ts (compat re-export)
   types.ts
   test-openviking-context-plugin.js
   openviking-tool.ts
   openviking-tool.js
   setup-wizard.sh
   daemon.sh
   Compatibility / rollback
   Feature flags (compatible with existing behavior):

TINYCLAW_OPENVIKING_CONTEXT_PLUGIN=0 (disable OpenViking context plugin entirely)
TINYCLAW_OPENVIKING_SESSION_NATIVE=1
TINYCLAW_OPENVIKING_SEARCH_NATIVE=1
TINYCLAW_OPENVIKING_PREFETCH=1
TINYCLAW_OPENVIKING_AUTOSYNC=1
If native/plugin flags are disabled, behavior falls back to non-OpenViking / legacy-compatible path.

Validation notes
Build passes:
npm run build:main
Regression passes:
npm run test:prefetch-parser
New pluginization integration tests pass:
npm run test:openviking-plugin
covers:
plugin disabled: no OpenViking calls
plugin enabled: native session + search + context injection
plugin failure: fallback path still works and is observable
Risk / follow-up
OpenViking latency (prefetch/commit) is environment-sensitive; timeout tuning may still be needed.
With stacked PR merge progression, diff should further collapse to OpenViking incremental changes only.