feat(timeline): add entity-direct seeding (issue:N, mr:N syntax)

Adds issue:N / i:N / mr:N / m:N query syntax to bypass hybrid search
and seed the timeline directly from a known entity. All discussions for
the entity are gathered without needing Ollama.

- parse_timeline_query() detects entity-direct patterns
- resolve_entity_by_iid() resolves IID to EntityRef with ambiguity handling
- seed_timeline_direct() gathers all discussions for the entity
- 20 new tests (5 resolve, 6 direct seed, 9 parse)
- Updated CLI help text and robot-docs manifest

src/core/timeline_seed.rs

@@ -5,8 +5,8 @@ use tracing::debug;
 
 use crate::core::error::Result;
 use crate::core::timeline::{
-    EntityRef, MatchedDiscussion, TimelineEvent, TimelineEventType, resolve_entity_ref,
-    truncate_to_chars,
+    EntityRef, MatchedDiscussion, TimelineEvent, TimelineEventType, resolve_entity_by_iid,
+    resolve_entity_ref, truncate_to_chars,
 };
 use crate::embedding::ollama::OllamaClient;
 use crate::search::{FtsQueryMode, SearchFilters, SearchMode, search_hybrid, to_fts_query};
@@ -102,6 +102,53 @@ pub async fn seed_timeline(
     })
 }
 
+/// Seed the timeline directly from an entity IID, bypassing search entirely.
+///
+/// Used for `issue:42` / `mr:99` syntax. Resolves the entity, gathers ALL its
+/// discussions, and returns a `SeedResult` compatible with the rest of the pipeline.
+pub fn seed_timeline_direct(
+    conn: &Connection,
+    entity_type: &str,
+    iid: i64,
+    project_id: Option<i64>,
+) -> Result<SeedResult> {
+    let entity_ref = resolve_entity_by_iid(conn, entity_type, iid, project_id)?;
+
+    // Gather all discussions for this entity (not search-matched, ALL of them)
+    let entity_id_col = match entity_type {
+        "issue" => "issue_id",
+        "merge_request" => "merge_request_id",
+        _ => {
+            return Ok(SeedResult {
+                seed_entities: vec![entity_ref],
+                evidence_notes: Vec::new(),
+                matched_discussions: Vec::new(),
+                search_mode: "direct".to_owned(),
+            });
+        }
+    };
+
+    let sql = format!("SELECT id, project_id FROM discussions WHERE {entity_id_col} = ?1");
+    let mut stmt = conn.prepare(&sql)?;
+    let matched_discussions: Vec<MatchedDiscussion> = stmt
+        .query_map(rusqlite::params![entity_ref.entity_id], |row| {
+            Ok(MatchedDiscussion {
+                discussion_id: row.get(0)?,
+                entity_type: entity_type.to_owned(),
+                entity_id: entity_ref.entity_id,
+                project_id: row.get(1)?,
+            })
+        })?
+        .collect::<std::result::Result<Vec<_>, _>>()?;
+
+    Ok(SeedResult {
+        seed_entities: vec![entity_ref],
+        evidence_notes: Vec::new(),
+        matched_discussions,
+        search_mode: "direct".to_owned(),
+    })
+}
+
 /// Resolve a list of document IDs to deduplicated entity refs and matched discussions.
 /// Discussion and note documents are resolved to their parent entity (issue or MR).
 /// Returns (entities, matched_discussions).