feat(ssa): Complete Phase I-IV intelligent dialogue and tool system development

Phase I - Session Blackboard + READ Layer:
- SessionBlackboardService with Postgres-Only cache
- DataProfileService for data overview generation
- PicoInferenceService for LLM-driven PICO extraction
- Frontend DataContextCard and VariableDictionaryPanel
- E2E tests: 31/31 passed

Phase II - Conversation Layer LLM + Intent Router:
- ConversationService with SSE streaming
- IntentRouterService (rule-first + LLM fallback, 6 intents)
- SystemPromptService with 6-segment dynamic assembly
- TokenTruncationService for context management
- ChatHandlerService as unified chat entry
- Frontend SSAChatPane and useSSAChat hook
- E2E tests: 38/38 passed

Phase III - Method Consultation + AskUser Standardization:
- ToolRegistryService with Repository Pattern
- MethodConsultService with DecisionTable + LLM enhancement
- AskUserService with global interrupt handling
- Frontend AskUserCard component
- E2E tests: 13/13 passed

Phase IV - Dialogue-Driven Analysis + QPER Integration:
- ToolOrchestratorService (plan/execute/report)
- analysis_plan SSE event for WorkflowPlan transmission
- Dual-channel confirmation (ask_user card + workspace button)
- PICO as optional hint for LLM parsing
- E2E tests: 25/25 passed

R Statistics Service:
- 5 new R tools: anova_one, baseline_table, fisher, linear_reg, wilcoxon
- Enhanced guardrails and block helpers
- Comprehensive test suite (run_all_tools_test.js)

Documentation:
- Updated system status document (v5.9)
- Updated SSA module status and development plan (v1.8)

Total E2E: 107/107 passed (Phase I: 31, Phase II: 38, Phase III: 13, Phase IV: 25)

Co-authored-by: Cursor <cursoragent@cursor.com>

r-statistics-service/tests/test_anova_one.json

@@ -0,0 +1,20 @@
+{
+  "data_source": {
+    "type": "inline",
+    "data": {
+      "group": ["A", "A", "A", "A", "A", "A", "A", "A", "A", "A",
+                 "B", "B", "B", "B", "B", "B", "B", "B", "B", "B",
+                 "C", "C", "C", "C", "C", "C", "C", "C", "C", "C"],
+      "score": [23, 25, 27, 24, 22, 26, 28, 21, 29, 24,
+                30, 32, 35, 31, 28, 33, 36, 29, 34, 31,
+                18, 20, 22, 19, 17, 21, 23, 16, 24, 19]
+    }
+  },
+  "params": {
+    "group_var": "group",
+    "value_var": "score"
+  },
+  "guardrails": {
+    "check_normality": true
+  }
+}