docs: fix documentation-source mismatches across all doc files

- Go version: 1.19+/1.21+ → 1.25+ (matches go.mod)
- document/doc.go → document/document.go (actual filename)
- PluginSDK: 3 channels → 4 channels (add RegisterOutputChannel)
- InjectInput/InjectInterrupt: 3 params → 4 params (add eventType)
- RegisterChannel: document agentIO.Device interface requirement
- Architecture: remove non-existent snapshot/tokenizer dirs, add skill/meta
- Architecture: fix double internal/internal/sdk, fix Jaccard threshold
- Adapter: add http_get/http_post Lua VM built-ins
- Knowledge: 4-layer → 3-layer memory, CGO for go-sqlite3 not overlayfs
- Code structure tree: fix sdk/ and lua/adapters/ path consistency

docs/en/ADAPTER.md

@@ -82,6 +82,10 @@ return adapter
 
 `log(level, message)` — Output log (level: info/warn/error)
 
+`http_get(url)` — Perform HTTP GET request, returns response body as string
+
+`http_post(url, body)` — Perform HTTP POST request, returns response body as string
+
 ## Adapting Typical APIs
 
 | API | endpoint | auth method | Format differences |