feat: add OpenAI/Anthropic tools support with tool emulation

- Parse tools/tool_choice from OpenAI and Anthropic requests
- Inject tool definitions into system prompt via toolemulation
- Parse action blocks (```json action) from model responses
- Retry logic for forced tool_choice (any/required)
- Return proper tool_calls / tool_use in responses
- Support streaming tools via collect-and-replay pattern
- Add tool history projection (assistant tool_calls + tool results)
- Model ID normalization: use official names (Qwen3.6-Plus, etc.)
- Fix resolveSessionMode to use Fresh mode when tools present

internal/lingmaipc/client.go

@@ -17,9 +17,6 @@ import (
 )
 
 const (
-	PipeDir    = `\\.\pipe\`
-	PipePrefix = "lingma-"
-
 	MetaRequestID       = "ai-coding/request-id"
 	MetaMode            = "ai-coding/mode"
 	MetaModel           = "ai-coding/model"