feat(me): add mentions section for @-mentions in dashboard

Add a new --mentions flag to the `lore me` command that surfaces items
where the user is @-mentioned but NOT already assigned, authoring, or
reviewing. This fills an important gap in the personal work dashboard:
cross-team requests and callouts that don't show up in the standard
issue/MR sections.

Implementation details:
- query_mentioned_in() scans notes for @username patterns, then filters
  out entities where the user is already an assignee, author, or reviewer
- MentionedInItem type captures entity_type (issue/mr), iid, title, state,
  project path, attention state, and updated timestamp
- Attention state computation marks items as needs_attention when there's
  recent activity from others
- Recency cutoff (7 days) prevents surfacing stale mentions
- Both human and robot renderers include the new section

The robot mode schema adds mentioned_in array with me_mentions field
preset for token-efficient output.

Test coverage:
- mentioned_in_finds_mention_on_unassigned_issue: basic case
- mentioned_in_excludes_assigned_issue: no duplicate surfacing
- mentioned_in_excludes_author_on_mr: author already sees in authored MRs
- mentioned_in_excludes_reviewer_on_mr: reviewer already sees in reviewing
- mentioned_in_uses_recency_cutoff: old mentions filtered
- mentioned_in_respects_project_filter: scoping works

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/cli/commands/me/render_robot.rs

@@ -4,8 +4,8 @@ use crate::cli::robot::RobotMeta;
 use crate::core::time::ms_to_iso;
 
 use super::types::{
-    ActivityEventType, AttentionState, MeActivityEvent, MeDashboard, MeIssue, MeMr, MeSummary,
-    SinceCheckEvent, SinceCheckGroup, SinceLastCheck,
+    ActivityEventType, AttentionState, MeActivityEvent, MeDashboard, MeIssue, MeMention, MeMr,
+    MeSummary, SinceCheckEvent, SinceCheckGroup, SinceLastCheck,
 };
 
 // ─── Robot JSON Output (Task #18) ────────────────────────────────────────────
@@ -28,11 +28,15 @@ pub fn print_me_json(
     // Apply --fields filtering (Task #19)
     if let Some(f) = fields {
         let expanded = crate::cli::robot::expand_fields_preset(f, "me_items");
-        // Filter all item arrays
+        // Filter issue/MR arrays with the items preset
         for key in &["open_issues", "open_mrs_authored", "reviewing_mrs"] {
             crate::cli::robot::filter_fields(&mut value, key, &expanded);
         }
 
+        // Mentioned-in gets its own preset (needs entity_type + state to disambiguate)
+        let mentions_expanded = crate::cli::robot::expand_fields_preset(f, "me_mentions");
+        crate::cli::robot::filter_fields(&mut value, "mentioned_in", &mentions_expanded);
+
         // Activity gets its own minimal preset
         let activity_expanded = crate::cli::robot::expand_fields_preset(f, "me_activity");
         crate::cli::robot::filter_fields(&mut value, "activity", &activity_expanded);
@@ -84,6 +88,7 @@ struct MeDataJson {
     open_issues: Vec<IssueJson>,
     open_mrs_authored: Vec<MrJson>,
     reviewing_mrs: Vec<MrJson>,
+    mentioned_in: Vec<MentionJson>,
     activity: Vec<ActivityJson>,
 }
 
@@ -97,6 +102,7 @@ impl MeDataJson {
             open_issues: d.open_issues.iter().map(IssueJson::from).collect(),
             open_mrs_authored: d.open_mrs_authored.iter().map(MrJson::from).collect(),
             reviewing_mrs: d.reviewing_mrs.iter().map(MrJson::from).collect(),
+            mentioned_in: d.mentioned_in.iter().map(MentionJson::from).collect(),
             activity: d.activity.iter().map(ActivityJson::from).collect(),
         }
     }
@@ -110,6 +116,7 @@ struct SummaryJson {
     open_issue_count: usize,
     authored_mr_count: usize,
     reviewing_mr_count: usize,
+    mentioned_in_count: usize,
     needs_attention_count: usize,
 }
 
@@ -120,6 +127,7 @@ impl From<&MeSummary> for SummaryJson {
             open_issue_count: s.open_issue_count,
             authored_mr_count: s.authored_mr_count,
             reviewing_mr_count: s.reviewing_mr_count,
+            mentioned_in_count: s.mentioned_in_count,
             needs_attention_count: s.needs_attention_count,
         }
     }
@@ -134,6 +142,7 @@ struct IssueJson {
     title: String,
     state: String,
     attention_state: String,
+    attention_reason: String,
     status_name: Option<String>,
     labels: Vec<String>,
     updated_at_iso: String,
@@ -148,6 +157,7 @@ impl From<&MeIssue> for IssueJson {
             title: i.title.clone(),
             state: "opened".to_string(),
             attention_state: attention_state_str(&i.attention_state),
+            attention_reason: i.attention_reason.clone(),
             status_name: i.status_name.clone(),
             labels: i.labels.clone(),
             updated_at_iso: ms_to_iso(i.updated_at),
@@ -165,6 +175,7 @@ struct MrJson {
     title: String,
     state: String,
     attention_state: String,
+    attention_reason: String,
     draft: bool,
     detailed_merge_status: Option<String>,
     author_username: Option<String>,
@@ -181,6 +192,7 @@ impl From<&MeMr> for MrJson {
             title: m.title.clone(),
             state: "opened".to_string(),
             attention_state: attention_state_str(&m.attention_state),
+            attention_reason: m.attention_reason.clone(),
             draft: m.draft,
             detailed_merge_status: m.detailed_merge_status.clone(),
             author_username: m.author_username.clone(),
@@ -191,6 +203,37 @@ impl From<&MeMr> for MrJson {
     }
 }
 
+// ─── Mention ─────────────────────────────────────────────────────────────
+
+#[derive(Serialize)]
+struct MentionJson {
+    entity_type: String,
+    project: String,
+    iid: i64,
+    title: String,
+    state: String,
+    attention_state: String,
+    attention_reason: String,
+    updated_at_iso: String,
+    web_url: Option<String>,
+}
+
+impl From<&MeMention> for MentionJson {
+    fn from(m: &MeMention) -> Self {
+        Self {
+            entity_type: m.entity_type.clone(),
+            project: m.project_path.clone(),
+            iid: m.iid,
+            title: m.title.clone(),
+            state: m.state.clone(),
+            attention_state: attention_state_str(&m.attention_state),
+            attention_reason: m.attention_reason.clone(),
+            updated_at_iso: ms_to_iso(m.updated_at),
+            web_url: m.web_url.clone(),
+        }
+    }
+}
+
 // ─── Activity ────────────────────────────────────────────────────────────────
 
 #[derive(Serialize)]
@@ -365,6 +408,7 @@ mod tests {
             title: "Fix auth bug".to_string(),
             project_path: "group/repo".to_string(),
             attention_state: AttentionState::NeedsAttention,
+            attention_reason: "Others commented recently; you haven't replied".to_string(),
             status_name: Some("In progress".to_string()),
             labels: vec!["bug".to_string()],
             updated_at: 1_700_000_000_000,
@@ -373,6 +417,10 @@ mod tests {
         let json = IssueJson::from(&issue);
         assert_eq!(json.iid, 42);
         assert_eq!(json.attention_state, "needs_attention");
+        assert_eq!(
+            json.attention_reason,
+            "Others commented recently; you haven't replied"
+        );
         assert_eq!(json.state, "opened");
         assert_eq!(json.status_name, Some("In progress".to_string()));
     }
@@ -384,6 +432,7 @@ mod tests {
             title: "Add feature".to_string(),
             project_path: "group/repo".to_string(),
             attention_state: AttentionState::AwaitingResponse,
+            attention_reason: "You replied moments ago; awaiting others".to_string(),
             draft: true,
             detailed_merge_status: Some("mergeable".to_string()),
             author_username: Some("alice".to_string()),
@@ -394,6 +443,10 @@ mod tests {
         let json = MrJson::from(&mr);
         assert_eq!(json.iid, 99);
         assert_eq!(json.attention_state, "awaiting_response");
+        assert_eq!(
+            json.attention_reason,
+            "You replied moments ago; awaiting others"
+        );
         assert!(json.draft);
         assert_eq!(json.author_username, Some("alice".to_string()));
     }