feat(campaign): govern attachment reuse

webui/src/features/campaigns/AttachmentsDataPage.tsx

@@ -58,6 +58,9 @@ export default function AttachmentsDataPage({ settings, campaignId }: {settings:
   const basePaths = useMemo(() => normalizeAttachmentBasePaths(attachments.base_paths, attachments), [attachments]);
   const globalRules = useMemo(() => normalizeAttachmentRules(attachments.global), [attachments.global]);
   const zipConfig = useMemo(() => normalizeAttachmentZipCollection(attachments.zip), [attachments.zip]);
+  const reusePolicy = asRecord(attachments.reuse_policy);
+  const reuseAction = ["allow", "warn", "review", "block"].includes(String(reusePolicy.action)) ? String(reusePolicy.action) : "allow";
+  const reuseAllowance = ["same_recipient", "same_message"].includes(String(reusePolicy.allow_within)) ? String(reusePolicy.allow_within) : "none";
   const residualFiles = asRecord(attachments.residual_files);
   const residualMode = ["report", "attach"].includes(String(residualFiles.mode)) ? String(residualFiles.mode) : "none";
   const residualRecipient = asRecord(residualFiles.recipient);
@@ -113,6 +116,16 @@ export default function AttachmentsDataPage({ settings, campaignId }: {settings:
     });
   }
 
+  function patchReusePolicy(next: Record<string, unknown>) {
+    if (locked) return;
+    patch(["attachments", "reuse_policy"], {
+      action: "allow",
+      allow_within: "none",
+      ...reusePolicy,
+      ...next
+    });
+  }
+
   function patchBasePath(index: number, patch: Partial<AttachmentBasePath>) {
     patchBasePaths(basePaths.map((basePath, currentIndex) => currentIndex === index ? { ...basePath, ...patch } : basePath));
   }
@@ -306,6 +319,29 @@ export default function AttachmentsDataPage({ settings, campaignId }: {settings:
             </div>
           </Card>
 
+          <Card title="Attachment reuse policy" collapsible>
+            <div className="campaign-residual-file-form">
+              <FormField label="Duplicate-file action" help="Applied when the same resolved source file appears more than once outside the configured allowance.">
+                <select value={reuseAction} disabled={locked} onChange={(event) => patchReusePolicy({ action: event.target.value })}>
+                  <option value="allow">Allow and record</option>
+                  <option value="warn">Allow with warning</option>
+                  <option value="review">Require explicit review</option>
+                  <option value="block">Block delivery</option>
+                </select>
+              </FormField>
+              <FormField label="Allowed reuse boundary" help="A boundary is an exception to the selected action. No exception applies the action to every repeated use.">
+                <select value={reuseAllowance} disabled={locked} onChange={(event) => patchReusePolicy({ allow_within: event.target.value })}>
+                  <option value="none">No exception</option>
+                  <option value="same_recipient">Within the same recipient</option>
+                  <option value="same_message">Within the same built message</option>
+                </select>
+              </FormField>
+            </div>
+            <DismissibleAlert tone={reuseAction === "block" ? "warning" : "info"} dismissible={false} compact>
+              Every repeated-file finding is retained in the build protocol. Review requires a reason bound to the exact build; Block prevents affected messages from being queued.
+            </DismissibleAlert>
+          </Card>
+
           <Card title="Unassigned file disposition" collapsible>
             <div className="campaign-residual-file-form">
               <FormField label="Action" help="Only sources with Unsent enabled are inspected. The existing warning policy remains active when no disposition is selected.">