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/PLUGIN_DEV.md

@@ -265,10 +265,10 @@ s.Settings().GetPlugin("other_plugin", "some_key")
 
 ```go
 // Queued delivery (processed in order)
-s.InjectInput(source, channel string, payload map[string]interface{})
+s.InjectInput(source, channel, eventType string, payload map[string]interface{})
 
 // Interrupt delivery (can interrupt current LLM processing)
-s.InjectInterrupt(source, channel string, payload map[string]interface{})
+s.InjectInterrupt(source, channel, eventType string, payload map[string]interface{})
 
 // Shortcuts
 s.InjectText(source, channel, text string)
@@ -318,7 +318,15 @@ s.Publish(&events.Event{
 #### IO Channel Management (built-in plugins)
 
 ```go
-// Register a channel (bind device driver)
+// Register a channel (bind device driver), dev must implement the agentIO.Device interface:
+//   Name() string
+//   Type() DeviceType
+//   Description() string
+//   Tools() []ToolDef
+//   Execute(tool string, args map[string]interface{}) (interface{}, error)
+//   Start() error
+//   Stop() error
+//   OutputCapabilities() OutputCapability
 s.RegisterChannel("mydevice", deviceImpl)
 
 // Unregister a channel