feat(flywheel): predict_task_risk 风险画像 MCP 工具——预测层落地

- 新增 commands/risk.rs：scope 级（前缀匹配子 scope）+ 文件级
  （commit_files JOIN commit_metrics）历史返工率聚合
- classify_risk 分级：返工率 ≥0.35 high、≥0.15 medium、其余 low；
  有效返工率取 scope 与文件（样本 ≥3）的较高者
- 可信度防线：样本 <5 或 conventional 率 <0.5（脏历史）→
  confidence=low 并附原因 notes，不让脏数据装可信
- CI 自修 commit（is_ci_auto）不计返工，与 L0 口径一致
- MCP 注册 predict_task_risk：agent 开工前按任务卡 scope/files
  查询风险，工具清单测试断言驻军
- 7 个单测（in-memory DB + conn 注入），90 全绿

Rules-Applied: R01,R06,R07,R13

.blueprint/modules/flywheel-intelligence.md

@@ -167,8 +167,9 @@
 - files: src-tauri/src/commands/commit_metrics.rs, src-tauri/src/commands/buff.rs, src-tauri/src/db.rs
 - acceptance: "[cargo test] 新表 commit_files(sha,path 联合主键) migration 到位（R05），git log --name-only 解析纯函数单测覆盖多 commit 多文件；[Tauri command] ingest_full_git_history 对炼境自身重跑 → commit_files 行数 >0 且重跑幂等（行数不变）"
 
-### 📋 P3-C. risk.rs 风险画像 + predict_task_risk MCP 工具
-- status: todo
+### ✅ P3-C. risk.rs 风险画像 + predict_task_risk MCP 工具
+- status: done
+- done_note: 2026-07-04 完成。commands/risk.rs：scope 级（前缀匹配子 scope）+ 文件级（commit_files JOIN）返工率聚合，classify_risk 阈值 ≥0.35 high / ≥0.15 medium；样本 <5 或 conventional 率 <0.5（脏历史）→ confidence=low 并附 notes；CI 自修剔除。MCP 工具 schema+dispatch+清单断言。7 个单测（高返工 scope/小样本/脏历史/热点文件/CI 剔除/入参校验/阈值），90 全绿。MCP 实调待新 build 重启后终验
 - complexity: M
 - depends: flywheel-intelligence（卡 P3-B）
 - files: src-tauri/src/commands/risk.rs, src-tauri/src/commands/mod.rs, src-tauri/src/mcp_tools.rs

src-tauri/src/commands/mod.rs

@@ -18,6 +18,7 @@ pub mod cicd;
 pub mod blueprint;
 pub mod buff;
 pub mod commit_metrics;
+pub mod risk;
 pub mod onboarding;
 pub mod canvas;
 pub mod claude_config;

src-tauri/src/commands/risk.rs

@@ -0,0 +1,297 @@
+//! 飞轮阶段三：执行质量风险画像（预测层）。
+//!
+//! 从 commit_metrics（scope 级）+ commit_files（文件级）聚合历史返工率，
+//! 供 agent 开工前通过 MCP 工具 `predict_task_risk` 评估任务风险。
+//! 全部查询走 conn 注入（R06），聚合与分级逻辑可用 in-memory DB 独立单测。
+
+use rusqlite::Connection;
+use serde::Serialize;
+
+/// scope 级返工画像。
+#[derive(Debug, Serialize)]
+pub struct ScopeRisk {
+    pub scope: String,
+    pub commits: u32,
+    pub rework: u32,
+    pub rework_rate: f64,
+}
+
+/// 单文件返工画像。
+#[derive(Debug, Serialize)]
+pub struct FileRisk {
+    pub path: String,
+    pub commits: u32,
+    pub rework: u32,
+    pub rework_rate: f64,
+}
+
+/// predict_task_risk 的完整返回。
+#[derive(Debug, Serialize)]
+pub struct TaskRiskPrediction {
+    pub project_id: String,
+    pub scope_stats: Option<ScopeRisk>,
+    pub file_stats: Vec<FileRisk>,
+    /// 结论依据的样本量（scope 命中 commit 数；无 scope 时取文件最大命中数）
+    pub sample_size: u32,
+    /// low = 样本 <5 或历史数据脏（conventional 率 <0.5），结论仅供参考
+    pub confidence: String,
+    /// low / medium / high，取 scope 与文件返工率的较高者分级
+    pub risk_level: String,
+    pub notes: Vec<String>,
+}
+
+/// 返工率分级阈值：≥0.35 high、≥0.15 medium、其余 low。纯函数。
+pub fn classify_risk(rate: f64) -> &'static str {
+    if rate >= 0.35 {
+        "high"
+    } else if rate >= 0.15 {
+        "medium"
+    } else {
+        "low"
+    }
+}
+
+fn rate(rework: u32, commits: u32) -> f64 {
+    if commits == 0 {
+        0.0
+    } else {
+        (rework as f64 / commits as f64 * 1000.0).round() / 1000.0
+    }
+}
+
+/// scope 级聚合：精确匹配或前缀匹配（"auth" 命中 "auth" 与 "auth/login"）。
+fn scope_risk(conn: &Connection, project_id: &str, scope: &str) -> Result<Option<ScopeRisk>, String> {
+    let (commits, rework): (u32, u32) = conn
+        .query_row(
+            "SELECT COUNT(*),
+                    COALESCE(SUM(CASE WHEN is_rework = 1 AND is_ci_auto = 0 THEN 1 ELSE 0 END), 0)
+             FROM commit_metrics
+             WHERE project_id = ?1 AND (scope = ?2 OR scope LIKE ?2 || '/%')",
+            rusqlite::params![project_id, scope],
+            |r| Ok((r.get(0)?, r.get(1)?)),
+        )
+        .map_err(|e| e.to_string())?;
+    if commits == 0 {
+        return Ok(None);
+    }
+    Ok(Some(ScopeRisk {
+        scope: scope.to_string(),
+        rework_rate: rate(rework, commits),
+        commits,
+        rework,
+    }))
+}
+
+/// 文件级聚合：每个文件在该项目历史中被多少 commit 触碰、其中多少是返工。
+fn file_risks(conn: &Connection, project_id: &str, files: &[String]) -> Result<Vec<FileRisk>, String> {
+    let mut result = Vec::new();
+    for path in files {
+        let (commits, rework): (u32, u32) = conn
+            .query_row(
+                "SELECT COUNT(*),
+                        COALESCE(SUM(CASE WHEN cm.is_rework = 1 AND cm.is_ci_auto = 0 THEN 1 ELSE 0 END), 0)
+                 FROM commit_files cf
+                 JOIN commit_metrics cm ON cm.sha = cf.sha
+                 WHERE cm.project_id = ?1 AND cf.path = ?2",
+                rusqlite::params![project_id, path],
+                |r| Ok((r.get(0)?, r.get(1)?)),
+            )
+            .map_err(|e| e.to_string())?;
+        if commits > 0 {
+            result.push(FileRisk {
+                path: path.clone(),
+                rework_rate: rate(rework, commits),
+                commits,
+                rework,
+            });
+        }
+    }
+    // 返工次数降序，agent 一眼看到最烫的文件
+    result.sort_by(|a, b| b.rework.cmp(&a.rework));
+    Ok(result)
+}
+
+/// 核心入口：按 scope 和/或文件清单预测任务风险。
+pub fn predict_task_risk(
+    conn: &Connection,
+    project_id: &str,
+    scope: Option<&str>,
+    files: &[String],
+) -> Result<TaskRiskPrediction, String> {
+    if scope.is_none() && files.is_empty() {
+        return Err("scope 与 files 至少提供一个".to_string());
+    }
+
+    let scope_stats = match scope {
+        Some(s) if !s.trim().is_empty() => scope_risk(conn, project_id, s.trim())?,
+        _ => None,
+    };
+    let file_stats = file_risks(conn, project_id, files)?;
+
+    let mut notes = Vec::new();
+
+    // 脏历史检测：conventional 率 <0.5 时结论不可信（数据可信度提示，与 onboarding 卡 D 同源）
+    let (total, conv): (u32, u32) = conn
+        .query_row(
+            "SELECT COUNT(*),
+                    COALESCE(SUM(CASE WHEN commit_type IS NOT NULL THEN 1 ELSE 0 END), 0)
+             FROM commit_metrics WHERE project_id = ?1",
+            [project_id],
+            |r| Ok((r.get(0)?, r.get(1)?)),
+        )
+        .map_err(|e| e.to_string())?;
+    let dirty_history = total > 0 && (conv as f64 / total as f64) < 0.5;
+    if dirty_history {
+        notes.push(format!(
+            "历史数据脏：conventional 率 {:.0}%（{}/{}），建议种 lefthook 后以新数据为准",
+            conv as f64 / total as f64 * 100.0,
+            conv,
+            total
+        ));
+    }
+
+    let sample_size = scope_stats
+        .as_ref()
+        .map(|s| s.commits)
+        .unwrap_or_else(|| file_stats.iter().map(|f| f.commits).max().unwrap_or(0));
+
+    // 有效返工率取 scope 与文件中的较高者（文件样本 ≥3 才参与，避免单次 fix 拉爆）
+    let scope_rate = scope_stats.as_ref().map(|s| s.rework_rate).unwrap_or(0.0);
+    let file_rate = file_stats
+        .iter()
+        .filter(|f| f.commits >= 3)
+        .map(|f| f.rework_rate)
+        .fold(0.0_f64, f64::max);
+    let effective_rate = scope_rate.max(file_rate);
+
+    let confidence = if sample_size < 5 || dirty_history {
+        if sample_size < 5 {
+            notes.push(format!("样本量 {sample_size} <5，结论仅供参考"));
+        }
+        "low"
+    } else {
+        "normal"
+    };
+
+    Ok(TaskRiskPrediction {
+        project_id: project_id.to_string(),
+        scope_stats,
+        file_stats,
+        sample_size,
+        confidence: confidence.to_string(),
+        risk_level: classify_risk(effective_rate).to_string(),
+        notes,
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::commands::commit_metrics::{record_commit_entry, GitLogEntry};
+
+    fn seed(conn: &Connection, pid: &str, sha: &str, subject: &str, files: &[&str]) {
+        let entry = GitLogEntry {
+            sha: sha.into(),
+            subject: subject.into(),
+            committed_at: "2026-07-04T00:00:00+09:00".into(),
+            rules_trailer: String::new(),
+            files: files.iter().map(|s| s.to_string()).collect(),
+        };
+        record_commit_entry(conn, pid, &entry).unwrap();
+    }
+
+    #[test]
+    fn classify_thresholds() {
+        assert_eq!(classify_risk(0.4), "high");
+        assert_eq!(classify_risk(0.35), "high");
+        assert_eq!(classify_risk(0.2), "medium");
+        assert_eq!(classify_risk(0.1), "low");
+    }
+
+    #[test]
+    fn high_rework_scope_flagged_high() {
+        let conn = crate::db::conn_with_schema();
+        // onboarding scope：6 commits 里 3 条 fix（含一个子 scope），返工率 0.5
+        for (i, subj) in [
+            "feat(onboarding): a",
+            "fix(onboarding): b",
+            "fix(onboarding/pack): c",
+            "feat(onboarding): d",
+            "fix(onboarding): e",
+            "chore(onboarding): f",
+        ]
+        .iter()
+        .enumerate()
+        {
+            seed(&conn, "p1", &format!("s{i}"), subj, &[]);
+        }
+        let r = predict_task_risk(&conn, "p1", Some("onboarding"), &[]).unwrap();
+        let s = r.scope_stats.unwrap();
+        assert_eq!(s.commits, 6, "前缀匹配应包含子 scope");
+        assert_eq!(s.rework, 3);
+        assert_eq!(r.risk_level, "high");
+        assert_eq!(r.confidence, "normal");
+    }
+
+    #[test]
+    fn small_sample_low_confidence() {
+        let conn = crate::db::conn_with_schema();
+        seed(&conn, "p1", "s1", "fix(auth): x", &[]);
+        seed(&conn, "p1", "s2", "feat(auth): y", &[]);
+        let r = predict_task_risk(&conn, "p1", Some("auth"), &[]).unwrap();
+        assert_eq!(r.confidence, "low");
+        assert!(r.notes.iter().any(|n| n.contains("样本量")), "应有小样本提示");
+    }
+
+    #[test]
+    fn dirty_history_noted_and_low_confidence() {
+        let conn = crate::db::conn_with_schema();
+        // 10 条里仅 3 条 conventional → 脏历史
+        for i in 0..7 {
+            seed(&conn, "p1", &format!("junk{i}"), "update stuff", &[]);
+        }
+        seed(&conn, "p1", "c1", "feat(api): a", &[]);
+        seed(&conn, "p1", "c2", "feat(api): b", &[]);
+        seed(&conn, "p1", "c3", "fix(api): c", &[]);
+        // api scope 样本 5 条以下也行，这里重点断言脏历史标记
+        let r = predict_task_risk(&conn, "p1", Some("api"), &[]).unwrap();
+        assert_eq!(r.confidence, "low");
+        assert!(r.notes.iter().any(|n| n.contains("历史数据脏")));
+    }
+
+    #[test]
+    fn file_level_rework_surfaces_hot_file() {
+        let conn = crate::db::conn_with_schema();
+        // hot.rs 被 4 个 commit 触碰，其中 2 个 fix；cold.rs 只有 feat
+        seed(&conn, "p1", "s1", "feat(a): x", &["src/hot.rs", "src/cold.rs"]);
+        seed(&conn, "p1", "s2", "fix(a): y", &["src/hot.rs"]);
+        seed(&conn, "p1", "s3", "fix(a): z", &["src/hot.rs"]);
+        seed(&conn, "p1", "s4", "feat(a): w", &["src/hot.rs"]);
+        let r = predict_task_risk(
+            &conn,
+            "p1",
+            None,
+            &["src/hot.rs".into(), "src/cold.rs".into(), "src/ghost.rs".into()],
+        )
+        .unwrap();
+        assert_eq!(r.file_stats.len(), 2, "无历史的文件不进结果");
+        assert_eq!(r.file_stats[0].path, "src/hot.rs", "返工多的文件排前");
+        assert_eq!(r.file_stats[0].rework, 2);
+        assert_eq!(r.risk_level, "high", "hot.rs 返工率 0.5 应分级 high");
+    }
+
+    #[test]
+    fn requires_scope_or_files() {
+        let conn = crate::db::conn_with_schema();
+        assert!(predict_task_risk(&conn, "p1", None, &[]).is_err());
+    }
+
+    #[test]
+    fn ci_auto_fix_excluded_from_rework() {
+        let conn = crate::db::conn_with_schema();
+        seed(&conn, "p1", "s1", "fix(ci): auto-fix [DeepSeek-V3]", &[]);
+        seed(&conn, "p1", "s2", "feat(ci): x", &[]);
+        let r = predict_task_risk(&conn, "p1", Some("ci"), &[]).unwrap();
+        assert_eq!(r.scope_stats.unwrap().rework, 0, "CI 自修不计返工");
+    }
+}

src-tauri/src/mcp_tools.rs

@@ -245,6 +245,19 @@ pub fn tools_list_result() -> Value {
                 "name": "scan_unregistered_projects",
                 "description": "扫描已登记项目的父目录，找出存在于文件系统但尚未在炼境注册的项目目录。返回每个未注册目录的路径、是否有 .git、技术栈特征文件（package.json / Cargo.toml / go.mod）、是否有 AGENTS.md。用于日常发现漏网项目并决定是否接入炼境。",
                 "inputSchema": { "type": "object", "properties": {}, "required": [] }
+            },
+            {
+                "name": "predict_task_risk",
+                "description": "任务风险预测（飞轮阶段三）：按 scope 和/或文件清单查询该项目历史返工率，返回 risk_level（low/medium/high）、样本量与置信度、热点文件排行。agent 开工前调用——任务卡涉及高返工 scope/文件时提高警惕（多写测试、小步提交）。样本 <5 或 commit 历史不规范时 confidence=low，结论仅供参考。",
+                "inputSchema": {
+                    "type": "object",
+                    "properties": {
+                        "project_id": { "type": "string", "description": "项目 workspace ID（来自 list_group_projects 的返回结果）" },
+                        "scope": { "type": "string", "description": "conventional commit scope（如 onboarding、auth/login），前缀匹配子 scope" },
+                        "files": { "type": "array", "items": { "type": "string" }, "description": "任务卡涉及的文件相对路径清单（与 git log --name-only 路径格式一致）" }
+                    },
+                    "required": ["project_id"]
+                }
             }
         ]
     })
@@ -462,6 +475,22 @@ pub async fn tools_call(group_id: &str, params: Option<&Value>) -> Value {
         }
         "list_all_projects" => list_all_projects(),
         "scan_unregistered_projects" => scan_unregistered_projects(),
+        "predict_task_risk" => {
+            let pid = args.get("project_id").and_then(|v| v.as_str()).unwrap_or("");
+            let scope = args.get("scope").and_then(|v| v.as_str());
+            let files: Vec<String> = args
+                .get("files")
+                .and_then(|v| v.as_array())
+                .map(|arr| {
+                    arr.iter()
+                        .filter_map(|f| f.as_str().map(str::to_string))
+                        .collect()
+                })
+                .unwrap_or_default();
+            let conn = db::pool().get().map_err(|e| e.to_string())?;
+            crate::commands::risk::predict_task_risk(&conn, pid, scope, &files)
+                .and_then(|r| serde_json::to_string_pretty(&r).map_err(|e| e.to_string()))
+        }
         "apply_onboarding_pack" => {
             let pid = args.get("project_id").and_then(|v| v.as_str()).unwrap_or("");
             resolve_project_root(&gid, pid).and_then(|root| {
@@ -1039,6 +1068,7 @@ mod tests {
         assert!(names.contains(&"inject_mcp"), "缺少 inject_mcp");
         assert!(names.contains(&"create_pull_request"), "缺少 create_pull_request");
         assert!(names.contains(&"poll_now"), "缺少 poll_now");
+        assert!(names.contains(&"predict_task_risk"), "缺少 predict_task_risk");
         // 每个工具都有 description 和 inputSchema
         for tool in tools {
             let name = tool["name"].as_str().unwrap_or("?");