feat(me): add "since last check" cursor-based inbox to dashboard

Implements a cursor-based notification inbox that surfaces actionable
events from others since the user's last `lore me` invocation. This
addresses the core UX need: "what happened while I was away?"

Event Sources (three-way UNION query):
1. Others' comments on user's open issues/MRs
2. @mentions on ANY item (not restricted to owned items)
3. Assignment/review-request system notes mentioning user

Mention Detection:
- SQL LIKE pre-filter for performance, then regex validation
- Word-boundary-aware: rejects "alice" in "@alice-bot" or "alice@corp.com"
- Domain rejection: "@alice.com" not matched (prevents email false positives)
- Punctuation tolerance: "@alice," "@alice." "(@ alice)" all match

Cursor Watermark Pattern:
- Global watermark computed from ALL projects before --project filtering
- Ensures --project display filter doesn't permanently skip events
- Cursor advances only after successful render (no data loss on errors)
- First run establishes baseline (no inbox shown), subsequent runs show delta

Output:
- Human: color-coded event badges, grouped by entity, actor + timestamp
- Robot: standard envelope with since_last_check object containing
  cursor_iso, total_event_count, and groups array with nested events

CLI additions:
- --reset-cursor flag: clears cursor (next run shows no new events)
- Autocorrect: --reset-cursor added to known me command flags

Tests cover:
- Mention with trailing comma/period/parentheses (should match)
- Email-like text "@alice.com" (should NOT match)  
- Domain-like text "@alice.example" (should NOT match)

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

src/cli/commands/me/render_robot.rs

@@ -5,6 +5,7 @@ use crate::core::time::ms_to_iso;
 
 use super::types::{
     ActivityEventType, AttentionState, MeActivityEvent, MeDashboard, MeIssue, MeMr, MeSummary,
+    SinceCheckEvent, SinceCheckGroup, SinceLastCheck,
 };
 
 // ─── Robot JSON Output (Task #18) ────────────────────────────────────────────
@@ -43,6 +44,27 @@ pub fn print_me_json(
     Ok(())
 }
 
+/// Print `--reset-cursor` response using standard robot envelope.
+pub fn print_cursor_reset_json(elapsed_ms: u64) -> crate::core::error::Result<()> {
+    let value = cursor_reset_envelope_json(elapsed_ms);
+    let json = serde_json::to_string(&value)
+        .map_err(|e| crate::core::error::LoreError::Other(format!("JSON serialization: {e}")))?;
+    println!("{json}");
+    Ok(())
+}
+
+fn cursor_reset_envelope_json(elapsed_ms: u64) -> serde_json::Value {
+    serde_json::json!({
+        "ok": true,
+        "data": {
+            "cursor_reset": true
+        },
+        "meta": {
+            "elapsed_ms": elapsed_ms
+        }
+    })
+}
+
 // ─── JSON Envelope ───────────────────────────────────────────────────────────
 
 #[derive(Serialize)]
@@ -57,6 +79,8 @@ struct MeDataJson {
     username: String,
     since_iso: Option<String>,
     summary: SummaryJson,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    since_last_check: Option<SinceLastCheckJson>,
     open_issues: Vec<IssueJson>,
     open_mrs_authored: Vec<MrJson>,
     reviewing_mrs: Vec<MrJson>,
@@ -69,6 +93,7 @@ impl MeDataJson {
             username: d.username.clone(),
             since_iso: d.since_ms.map(ms_to_iso),
             summary: SummaryJson::from(&d.summary),
+            since_last_check: d.since_last_check.as_ref().map(SinceLastCheckJson::from),
             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(),
@@ -197,6 +222,67 @@ impl From<&MeActivityEvent> for ActivityJson {
     }
 }
 
+// ─── Since Last Check ────────────────────────────────────────────────────────
+
+#[derive(Serialize)]
+struct SinceLastCheckJson {
+    cursor_iso: String,
+    total_event_count: usize,
+    groups: Vec<SinceCheckGroupJson>,
+}
+
+impl From<&SinceLastCheck> for SinceLastCheckJson {
+    fn from(s: &SinceLastCheck) -> Self {
+        Self {
+            cursor_iso: ms_to_iso(s.cursor_ms),
+            total_event_count: s.total_event_count,
+            groups: s.groups.iter().map(SinceCheckGroupJson::from).collect(),
+        }
+    }
+}
+
+#[derive(Serialize)]
+struct SinceCheckGroupJson {
+    entity_type: String,
+    entity_iid: i64,
+    entity_title: String,
+    project: String,
+    events: Vec<SinceCheckEventJson>,
+}
+
+impl From<&SinceCheckGroup> for SinceCheckGroupJson {
+    fn from(g: &SinceCheckGroup) -> Self {
+        Self {
+            entity_type: g.entity_type.clone(),
+            entity_iid: g.entity_iid,
+            entity_title: g.entity_title.clone(),
+            project: g.project_path.clone(),
+            events: g.events.iter().map(SinceCheckEventJson::from).collect(),
+        }
+    }
+}
+
+#[derive(Serialize)]
+struct SinceCheckEventJson {
+    timestamp_iso: String,
+    event_type: String,
+    actor: Option<String>,
+    summary: String,
+    body_preview: Option<String>,
+}
+
+impl From<&SinceCheckEvent> for SinceCheckEventJson {
+    fn from(e: &SinceCheckEvent) -> Self {
+        Self {
+            timestamp_iso: ms_to_iso(e.timestamp),
+            event_type: event_type_str(&e.event_type),
+            actor: e.actor.clone(),
+            summary: e.summary.clone(),
+            body_preview: e.body_preview.clone(),
+        }
+    }
+}
+
 // ─── Helpers ─────────────────────────────────────────────────────────────────
 
 /// Convert `AttentionState` to its programmatic string representation.
@@ -331,4 +417,12 @@ mod tests {
         assert!(!json.is_own);
         assert_eq!(json.body_preview, Some("This looks good".to_string()));
     }
+
+    #[test]
+    fn cursor_reset_envelope_includes_meta_elapsed_ms() {
+        let value = cursor_reset_envelope_json(17);
+        assert_eq!(value["ok"], serde_json::json!(true));
+        assert_eq!(value["data"]["cursor_reset"], serde_json::json!(true));
+        assert_eq!(value["meta"]["elapsed_ms"], serde_json::json!(17));
+    }
 }