Reorganize tool definitions into granular domain modules

**New structure:**
src/tools/definitions/
├── mod.rs         # Aggregates all 43 tools
├── system.rs      # 3 tools: healthcheck, verify_setup, list_symbols
├── experts.rs     # 4 tools: compile_ea, list_experts, list_indicators, list_scripts
├── backtest.rs    # 4 tools: run_backtest, get_backtest_status, cache_status, clean_cache
├── optimization.rs # 4 tools: run_optimization, get_optimization_status, get_optimization_results, list_jobs
├── analytics.rs   # 9 tools: analyze_report + 8 granular analytics
├── reports.rs     # 11 tools: list_reports, search_reports, get_latest_report, etc.
├── setfiles.rs    # 8 tools: read/write/patch/clone/diff set files
└── baseline.rs    # 1 tool: compare_baseline

**Benefits:**
- Domain-based organization (21KB monolith -> 9 focused files)
- Each domain can evolve independently
- Easier to find and modify tool definitions
- Clear separation between system, experts, backtest, optimization, analytics, reports, setfiles

src/tools/definitions/reports.rs

@@ -0,0 +1,150 @@
+use serde_json::{json, Value};
+
+pub fn tool_get_latest_report() -> Value {
+    json!({
+        "name": "get_latest_report",
+        "description": "Get the latest backtest report with full details and equity chart image",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "include_chart": { "type": "boolean", "description": "Include equity chart as base64 PNG (default: true)", "default": true }
+            }
+        }
+    })
+}
+
+pub fn tool_list_reports() -> Value {
+    json!({
+        "name": "list_reports",
+        "description": "List most recent backtest reports from the central registry (SQLite). Returns id, metrics, set file, chart paths.",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "limit": { "type": "integer", "description": "Max results (default 30)" }
+            }
+        }
+    })
+}
+
+pub fn tool_search_reports() -> Value {
+    json!({
+        "name": "search_reports",
+        "description": "Search backtest history with filters. All filters are optional and combinable.",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "expert": { "type": "string", "description": "EA name substring match" },
+                "symbol": { "type": "string", "description": "Exact symbol, e.g. XAUUSD" },
+                "timeframe": { "type": "string", "description": "Exact timeframe, e.g. M5" },
+                "after": { "type": "string", "description": "ISO8601 date — only reports created after this" },
+                "min_profit": { "type": "number", "description": "Minimum net profit" },
+                "max_dd": { "type": "number", "description": "Maximum drawdown %" },
+                "verdict": { "type": "string", "description": "Only reports with this verdict (pass, fail, marginal)" },
+                "limit": { "type": "integer", "default": 50 }
+            }
+        }
+    })
+}
+
+pub fn tool_tail_log() -> Value {
+    json!({
+        "name": "tail_log",
+        "description": "Stream the last N lines of a job log",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "job_id": { "type": "string" },
+                "file": { "type": "string" },
+                "lines": { "type": "integer", "default": 50 }
+            }
+        }
+    })
+}
+
+pub fn tool_archive_report() -> Value {
+    json!({
+        "name": "archive_report",
+        "description": "Compress a backtest report directory to tar.gz",
+        "inputSchema": {
+            "type": "object",
+            "required": ["report_dir"],
+            "properties": {
+                "report_dir": { "type": "string" },
+                "delete_after": { "type": "boolean" }
+            }
+        }
+    })
+}
+
+pub fn tool_archive_all_reports() -> Value {
+    json!({
+        "name": "archive_all_reports",
+        "description": "Archive all old reports except the N most recent",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "keep_last": { "type": "integer" }
+            }
+        }
+    })
+}
+
+pub fn tool_get_history() -> Value {
+    json!({
+        "name": "get_history",
+        "description": "Retrieve backtest history for an EA or symbol",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "ea": { "type": "string" },
+                "symbol": { "type": "string" },
+                "verdict": { "type": "string" },
+                "limit": { "type": "integer" }
+            }
+        }
+    })
+}
+
+pub fn tool_promote_to_baseline() -> Value {
+    json!({
+        "name": "promote_to_baseline",
+        "description": "Copy report metrics to config/baseline.json for future comparisons",
+        "inputSchema": {
+            "type": "object",
+            "required": ["report_dir"],
+            "properties": {
+                "report_dir": { "type": "string" }
+            }
+        }
+    })
+}
+
+pub fn tool_annotate_history() -> Value {
+    json!({
+        "name": "annotate_history",
+        "description": "Add notes, tags or verdict to a history entry",
+        "inputSchema": {
+            "type": "object",
+            "required": ["history_id"],
+            "properties": {
+                "history_id": { "type": "string" },
+                "notes": { "type": "string" },
+                "tags": { "type": "array", "items": { "type": "string" } },
+                "verdict": { "type": "string", "enum": ["pass", "fail", "marginal"] }
+            }
+        }
+    })
+}
+
+pub fn tool_prune_reports() -> Value {
+    json!({
+        "name": "prune_reports",
+        "description": "Delete old backtest report directories",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "keep_last": { "type": "integer" }
+            }
+        }
+    })
+}