missions: multi-team model — pick research + development teams

Directly addresses "we want to pick one or more teams to assign to a
mission, first screen research teams, next screen dev teams." A
mission now materializes N teams, each tagged with a phase purpose.

Backend:
  - 0056_mission_teams.sql — new join table
    mission_teams(mission_id, team_id, purpose). team_id PK because a
    team belongs to one mission-purpose. missions.team_id kept as
    legacy pointer to the first minted team for single-team surfaces.
  - mission_orchestrator::on_launch — reads mission.config.phase_teams
    (JSONB shape { research: [tid,...], coding: [tid,...] }), mints
    one team per (purpose, template) pair, records each in
    mission_teams, binds the first to mission.team_id. Legacy fallback:
    if config.phase_teams is absent, uses missions.team_template_id.
    Hard error if both are absent.
  - GET /api/missions/{id}/teams — returns
    [{ team_id, purpose, team_name }], sorted by created_at asc.

Frontend wizard (step 3 rewrite):
  - researchTeamIds / devTeamIds — Set<string> multi-selects
  - Reusable TeamMultiSelect component (checkbox-style cards)
  - Panels rendered conditionally by preset:
    hasResearchPhase → "Research teams" panel
    hasCodingPhase → "Development teams" panel
    neither → "Teams" panel (bench/security-only missions)
  - canNext enforces at least one pick in every visible panel
  - submit builds config.phase_teams and passes it via CreateMissionRequest
  - Review step shows both selections by name

MissionTeamTab:
  - Fetches /api/missions/{id}/teams and groups by purpose
  - Each purpose renders a section with per-team cards
  - Falls back to a single "mission" pseudo-row for legacy missions
    that only have missions.team_id (no mission_teams rows)

CreateMissionRequest no longer sends team_template_id from the wizard
— the multi-team config.phase_teams path supersedes it. The backend
still accepts team_template_id for API callers.

Verified: cargo check --workspace + tsc + eslint --quiet all green.

crates/cm-api/src/routes/missions.rs

@@ -410,6 +410,43 @@ pub async fn herdr_dispatch(
     }))
 }
 
+/// GET /api/missions/{id}/teams — teams materialized for this mission,
+/// grouped by purpose (research / coding / etc). Returns
+/// [{ purpose, team_id, team_name }] so the Team tab can render
+/// sections. The legacy single-team view falls back to
+/// mission.team_id when this array is empty.
+pub async fn list_teams(
+    State(state): State<AppState>,
+    Authed(user): Authed,
+    Path(id): Path<Uuid>,
+) -> Result<Json<Value>, ApiError> {
+    let _ = cm_db::repo::missions::get(&state.pool, id, user.workspace_id.as_uuid())
+        .await?
+        .ok_or(ApiError::NotFound)?;
+    use sqlx::Row;
+    let rows = sqlx::query(
+        "SELECT mt.team_id::text AS team_id, mt.purpose, t.name AS team_name
+         FROM mission_teams mt
+         JOIN teams t ON t.id = mt.team_id
+         WHERE mt.mission_id = $1
+         ORDER BY mt.created_at ASC",
+    )
+    .bind(id)
+    .fetch_all(&state.pool)
+    .await?;
+    let teams: Vec<Value> = rows
+        .into_iter()
+        .map(|r| {
+            serde_json::json!({
+                "team_id": r.get::<String, _>("team_id"),
+                "purpose": r.get::<String, _>("purpose"),
+                "team_name": r.get::<String, _>("team_name"),
+            })
+        })
+        .collect();
+    Ok(Json(serde_json::json!({ "teams": teams })))
+}
+
 /// GET /api/missions/{id}/runs — topology_runs bound to this mission,
 /// newest first. Used by the Live tab to subscribe to per-run SSE.
 pub async fn list_runs(