fix(ux): resolve tickets #51 #53 #54 from gitlooper sweep

- #51: Add permanent redirect /login → /auth/signin in next.config.ts
  so users/testers who type the common alias land on the correct auth page
- #53: Add "Allocations → New Planning Entry" link to empty states of
  ProjectDemandsTable and ProjectAssignmentsTable; add shortcut link in
  demands table header for canEdit users
- #54: Track confirmed dropdown selection in ResourcePersonPicker —
  green ring + checkmark icon shown when user picks from suggestions;
  cleared on any manual keypress so free-text is clearly unconfirmed

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/components/projects/ProjectAssignmentsTable.tsx

@@ -2,6 +2,7 @@
 
 import { useState, useMemo } from "react";
 import { useRouter } from "next/navigation";
+import Link from "next/link";
 import { formatCents, formatDate, formatMoney } from "~/lib/format.js";
 import { InfoTooltip } from "~/components/ui/InfoTooltip.js";
 import { ALLOCATION_STATUS_BADGE } from "~/lib/status-styles.js";
@@ -199,7 +200,18 @@ export function ProjectAssignmentsTable({ assignments }: ProjectAssignmentsTable
         })()}
       </table>
       {assignments.length === 0 && (
-        <div className="text-center py-12 text-gray-500 dark:text-gray-400 text-sm">No assignments for this project.</div>
+        <div className="text-center py-12 text-sm text-gray-500 dark:text-gray-400 space-y-2">
+          <p>No assignments for this project.</p>
+          {canEdit && (
+            <p>
+              Create staffing entries via{" "}
+              <Link href="/allocations" className="text-brand-600 hover:underline dark:text-brand-400">
+                Allocations → New Planning Entry
+              </Link>
+              .
+            </p>
+          )}
+        </div>
       )}
     </div>
   );