docs: api comments say what the endpoints do, not how they came to be (#6277)

Rewrites the internal/api comment blocks to rule 32: task, milestone and
rule ids gone, the stories behind them restated as the constraint they
left, stale references corrected (the stream secret is wired from config,
the timezone handler already refreshes the scheduler, the Android app is
the native client, the design docs cited are not in the repo). Also
rewraps comment lines over 80 columns left by the earlier batches.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/admin_quarantine.go

@@ -85,7 +85,8 @@ type actionResultView struct {
 	AffectedUsers int32  `json:"affected_users"`
 }
 
-// handleResolveQuarantine implements POST /api/admin/quarantine/{track_id}/resolve.
+// handleResolveQuarantine implements POST
+// /api/admin/quarantine/{track_id}/resolve.
 func (h *handlers) handleResolveQuarantine(w http.ResponseWriter, r *http.Request) {
 	admin, ok := auth.UserFromContext(r.Context())
 	if !ok {
@@ -115,7 +116,8 @@ func (h *handlers) handleResolveQuarantine(w http.ResponseWriter, r *http.Reques
 	})
 }
 
-// handleDeleteQuarantineFile implements POST /api/admin/quarantine/{track_id}/delete-file.
+// handleDeleteQuarantineFile implements POST
+// /api/admin/quarantine/{track_id}/delete-file.
 func (h *handlers) handleDeleteQuarantineFile(w http.ResponseWriter, r *http.Request) {
 	admin, ok := auth.UserFromContext(r.Context())
 	if !ok {
@@ -129,8 +131,8 @@ func (h *handlers) handleDeleteQuarantineFile(w http.ResponseWriter, r *http.Req
 	}
 	action, err := h.quarantine.DeleteFile(r.Context(), id, admin.ID)
 	if err != nil {
-		// Written in the enveloped shape, not writeAdminJSONErr's bare code: the
-		// message is the part that tells the operator which directory and uid.
+		// Written in the enveloped shape, not writeAdminJSONErr's bare code:
+		// the message is the part that tells an admin which directory and uid.
 		if apiErr, ok := fileRemoveAPIError(err); ok {
 			logFileRemoveFailure(h.logger, apiErr, "track_id", uuidToString(id))
 			writeErr(w, apiErr)