fix: resolve 17 P2 defects and 5 P3 defects from pre-launch audit

Batch fix covering multiple modules:
- P2-01: HandRegistry Semaphore-based max_concurrent enforcement
- P2-03: Populate toolCount/metricCount from Hand trait methods
- P2-06: heartbeat_update_config minimum interval validation
- P2-07: ReflectionResult used_fallback marker for rule-based fallback
- P2-08/09: identity_propose_change parameter naming consistency
- P2-10: ClassroomMetadata is_placeholder flag for LLM failure
- P2-11: classroomStore userDidCloseDuringGeneration intent tracking
- P2-12: workflowStore pipeline_create sends actionType
- P2-13/14: PipelineInfo step_count + PipelineStepInfo for proper step mapping
- P2-15: Pipe transform support in context.resolve (8 transforms)
- P2-16: Mustache {{...}} → \${...} auto-normalization
- P2-17: SaaSLogin password placeholder 6→8
- P2-19: serialize_skill_md + update_skill preserve tools field
- P2-22: ToolOutputGuard sensitive patterns from warn→block
- P2-23: Mutex::unwrap() → unwrap_or_else in relay/service.rs
- P3-01/03/07/08/09: Various P3 fixes
- DEFECT_LIST.md: comprehensive status sync (43/51 fixed, 8 remaining)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

desktop/src-tauri/src/pipeline_commands/discovery.rs

@@ -6,7 +6,6 @@ use tauri::{AppHandle, Emitter, State};
 use zclaw_pipeline::{
     RunStatus,
     parse_pipeline_yaml,
-    parse_pipeline_v2_yaml,
     PipelineExecutor,
     ActionRegistry,
     LlmActionDriver,
@@ -16,7 +15,7 @@ use zclaw_pipeline::{
 
 use super::{PipelineState, PipelineInfo, PipelineRunResponse, RunPipelineResponse, RunPipelineRequest};
 use super::adapters::{RuntimeLlmAdapter, PipelineSkillDriver, PipelineHandDriver};
-use super::helpers::{get_pipelines_directory, scan_pipelines_with_paths, scan_pipelines_full_sync, pipeline_to_info, pipeline_v2_to_info};
+use super::helpers::{get_pipelines_directory, scan_pipelines_with_paths, scan_pipelines_full_sync, pipeline_to_info};
 
 use crate::kernel_commands::KernelState;