Let an operator authenticate with a seeded key, and reset the schema

- TERDUT_OPERATOR_KEY creates or re-keys the instance-scoped service account
  "terdut-operator" at every start, so terdut-operator needs no bootstrap
  handshake. An instance-scoped account now acts as owner of every team's
  configuration, but is not a member of any team.
- POST /api/teams takes an external_id (instance service accounts only) and
  is idempotent on it, so automation finds its own team again after a crash
  instead of adopting by display name. GET /api/teams?name= is removed.
- Integration and dead man's switch names are unique per team (409). The
  escalation PUT accepts usernames and resolves them itself.
- The 18 migrations are squashed into 001_schema.sql, with no Default team.
  TERDUT_DEADMAN_* and the env seeding of switches are removed: teams carry
  their own. Existing development databases must be recreated.

Security and robustness:
- GET /api/users no longer returns other people's email or ntfy topic to
  non-admins.
- The access log records the route pattern, so integration keys and ack
  tokens in the path are not written to the log. Server errors are logged.
- Rate limits take the client address TERDUT_TRUSTED_PROXIES hops from the
  right of X-Forwarded-For instead of trusting the first, forgeable entry.
- /api/bootstrap runs in a transaction under an advisory lock, so two
  concurrent calls cannot both create an administrator.
- API key last_used_at is written at most every five minutes.

Cleanup: remove GET /api/incidents/{id}/alerts, unused exports, SQLite
remnants in comments and config.

Claude-Session: https://claude.ai/code/session_016mBLURvJoMuUEr9cB2RpUN

internal/api/schedule.go

@@ -69,7 +69,7 @@ func handleCreateSchedule(db *sql.DB) http.HandlerFunc {
 		// be, so the delete and the insert share one transaction.
 		tx, err := db.BeginTx(r.Context(), nil)
 		if err != nil {
-			respond(w, http.StatusInternalServerError, errResp("internal error"))
+			serverError(w, r, err)
 			return
 		}
 		defer tx.Rollback()
@@ -79,7 +79,7 @@ func handleCreateSchedule(db *sql.DB) http.HandlerFunc {
 				if _, err := tx.ExecContext(r.Context(),
 					"DELETE FROM schedule_entries WHERE team_id = $1 AND date = $2",
 					teamID, d); err != nil {
-					respond(w, http.StatusInternalServerError, errResp("internal error"))
+					serverError(w, r, err)
 					return
 				}
 			}
@@ -91,12 +91,12 @@ func handleCreateSchedule(db *sql.DB) http.HandlerFunc {
 						errResp("date already assigned: "+d+" (pass replace to take it)"))
 					return
 				}
-				respond(w, http.StatusInternalServerError, errResp("internal error"))
+				serverError(w, r, err)
 				return
 			}
 		}
 		if err := tx.Commit(); err != nil {
-			respond(w, http.StatusInternalServerError, errResp("internal error"))
+			serverError(w, r, err)
 			return
 		}
 
@@ -107,7 +107,7 @@ func handleCreateSchedule(db *sql.DB) http.HandlerFunc {
 		}
 		all, err := scheduleRange(r.Context(), db, teamID, req.Dates[0], req.Dates[len(req.Dates)-1])
 		if err != nil {
-			respond(w, http.StatusInternalServerError, errResp("internal error"))
+			serverError(w, r, err)
 			return
 		}
 		created := []models.ScheduleEntry{}
@@ -147,7 +147,7 @@ func handleListSchedule(db *sql.DB) http.HandlerFunc {
 
 		entries, err := scheduleRange(r.Context(), db, teamID, from, to)
 		if err != nil {
-			respond(w, http.StatusInternalServerError, errResp("internal error"))
+			serverError(w, r, err)
 			return
 		}
 		respond(w, http.StatusOK, entries)
@@ -171,7 +171,7 @@ func handleDeleteSchedule(db *sql.DB) http.HandlerFunc {
 		res, err := db.ExecContext(r.Context(),
 			"DELETE FROM schedule_entries WHERE id = $1 AND team_id = $2", id, teamID)
 		if err != nil {
-			respond(w, http.StatusInternalServerError, errResp("internal error"))
+			serverError(w, r, err)
 			return
 		}
 		if n, _ := res.RowsAffected(); n == 0 {
@@ -197,7 +197,7 @@ func handleCurrentSchedule(db *sql.DB) http.HandlerFunc {
 			WHERE  s.date = $1 AND s.team_id = ANY($2)
 			ORDER  BY t.name`, today, callerTeamIDs(r.Context()))
 		if err != nil {
-			respond(w, http.StatusInternalServerError, errResp("internal error"))
+			serverError(w, r, err)
 			return
 		}
 		defer rows.Close()
@@ -207,14 +207,14 @@ func handleCurrentSchedule(db *sql.DB) http.HandlerFunc {
 			var e models.ScheduleEntry
 			var ts int64
 			if err := rows.Scan(&e.ID, &e.TeamID, &e.TeamName, &e.UserID, &e.Username, &e.Date, &ts); err != nil {
-				respond(w, http.StatusInternalServerError, errResp("internal error"))
+				serverError(w, r, err)
 				return
 			}
 			e.CreatedAt = time.Unix(ts, 0).UTC()
 			entries = append(entries, e)
 		}
 		if err := rows.Err(); err != nil {
-			respond(w, http.StatusInternalServerError, errResp("internal error"))
+			serverError(w, r, err)
 			return
 		}
 		respond(w, http.StatusOK, entries)