feat: implement streaming chat, skill routing, and SAFe PI planning tools

- Add /api/chat/stream endpoint with Server-Sent Events (SSE) for real-time message streaming
  * Implement StreamEvent types (thought, tool_call, tool_result, final, error)
  * Add StreamEventCallback mechanism for event propagation
  * Create StreamChatHandler in webui/bot with proper HTTP headers and flushing

- Implement LLM-based skill router for intelligent capability selection
  * Add optional routerLLM client for semantic routing
  * Implement routeSkillsWithLLM() to match user intent to available skills
  * Add matchSkillsByName() for fuzzy skill matching
  * Update buildUnifiedSystemPrompt() to use routed skills

- Add streaming support to ReAct pipeline
  * Implement runUnifiedReActStream() for streaming thought/action/observation
  * Emit StreamEvent at each ReAct step
  * Support callback error handling in streaming mode

- Integrate three new DevOps tools
  * tools/filedoc: Extract document content from file_id via OpenAI
  * tools/giteaticket: Create Gitea issues from PI plan items with SAFe metadata
  * tools/piplan: Publish PI planning blueprints with dependency tracking

- Add SAFe PI Planning skill
  * Implement PM/SA/RTE (iron triangle) workflow
  * Support for Feature, Enabler, and Dependency definition
  * Automatic task decomposition and Gitea integration

- Create frontend integration documentation
  * Complete SSE protocol specification
  * TypeScript fetch + ReadableStream example
  * LLM-ready refactoring template for other projects

- Simplify file handling
  * Remove legacy file context structures and dual-mode processing
  * Consolidate file operations into UploadAndCacheFiles()
  * Remove FilePromptMode configuration and related complexity

- Update configuration
  * Add Router model support (LLM_ROUTER_MODEL)
  * Add Gitea configuration (BaseURL, Token, Owner, Repo)
  * WebSearch and additional tool infrastructure

Tests: All 22 test packages passing, 8/8 webui tests including 3 new stream tests

internal/toolhost/runtime.go

@@ -8,8 +8,11 @@ import (
 	"laodingbot/internal/config"
 	"laodingbot/internal/logger"
 	"laodingbot/internal/tools"
+	"laodingbot/tools/filedoc"
 	"laodingbot/tools/fileoperation"
 	"laodingbot/tools/git"
+	"laodingbot/tools/giteaticket"
+	"laodingbot/tools/piplan"
 	"laodingbot/tools/shell"
 	"laodingbot/tools/websearch"
 )
@@ -20,6 +23,9 @@ func RunChild(ctx context.Context, cfg config.Config, log *logger.Logger) error
 	var gitLog *logger.Logger
 	var shellLog *logger.Logger
 	var searchLog *logger.Logger
+	var fileDocLog *logger.Logger
+	var piPlanLog *logger.Logger
+	var giteaTicketLog *logger.Logger
 	var serverLog *logger.Logger
 	if log != nil {
 		log.Infof("toolhost child starting")
@@ -28,6 +34,9 @@ func RunChild(ctx context.Context, cfg config.Config, log *logger.Logger) error
 		gitLog = log.WithComponent("toolhost.git")
 		shellLog = log.WithComponent("toolhost.shell")
 		searchLog = log.WithComponent("toolhost.websearch")
+		fileDocLog = log.WithComponent("toolhost.filedoc")
+		piPlanLog = log.WithComponent("toolhost.piplan")
+		giteaTicketLog = log.WithComponent("toolhost.giteaticket")
 		serverLog = log.WithComponent("toolhost.server")
 	}
 	registry := tools.NewRegistry(registryLog)
@@ -53,6 +62,27 @@ func RunChild(ctx context.Context, cfg config.Config, log *logger.Logger) error
 		cfg.ToolOutputMaxChars,
 		searchLog,
 	))
+	registry.Register(filedoc.New(
+		filedoc.Config{
+			APIKey:  cfg.LLM.APIKey,
+			BaseURL: cfg.LLM.BaseURL,
+			Model:   cfg.LLM.FileModel,
+			Timeout: time.Duration(cfg.ToolCallTimeoutSec) * time.Second,
+		},
+		cfg.ToolOutputMaxChars,
+		fileDocLog,
+	))
+	registry.Register(piplan.New(cfg.ToolOutputMaxChars, piPlanLog))
+	registry.Register(giteaticket.New(
+		giteaticket.Config{
+			BaseURL: cfg.Gitea.BaseURL,
+			Token:   cfg.Gitea.Token,
+			Owner:   cfg.Gitea.Owner,
+			Repo:    cfg.Gitea.Repo,
+			Timeout: time.Duration(cfg.ToolCallTimeoutSec) * time.Second,
+		},
+		giteaTicketLog,
+	))
 
 	server := NewServer(registry, serverLog)
 	if err := server.Serve(ctx, stdin(), stdout()); err != nil && ctx.Err() == nil {