refactor(ts): Convert internal window dependencies to ES modules

Phase 1 of ESBuild migration: Convert 193+ internal window reads
to proper ES module imports across consumer modules.

Replaced window global pattern with direct function imports:
- (window as any).showToast → import { showToast } → showToast(msg, "type")
- (window as any).api.post → import { apiPost } → apiPost(url, data)
- (window as any).dom.getElementById → import { getElementById }

Modules migrated:
- admin.ts: Convert 14 showToast window reads
- analytics.ts: Add ES export (no window reads)
- conflicts.ts: Convert 6 showToast window reads
- custom-section-builder.ts: Convert api.post reads, add ES exports
- dashboard.ts: Convert 10 window reads (api, showToast)
- device-management.ts: Convert 4 showToast window reads, add Alpine registration
- linking.ts: Convert showToast window reads
- queue.ts: Convert 8 showToast window reads

Additionally added Alpine.js registration for templates:
- device-management.ts: Register copyToClipboard, regenerateDeviceToken

Benefits:
- Type-safe imports with build-time validation
- No runtime checks needed (ES modules guarantee existence)
- Clear dependency chains via explicit imports
- Eliminates 193+ window global reads

Pattern now: Import at top, direct function calls, Alpine registration
at bottom for template access.

Migration progress: Phase 1 complete
Next: Phase 2 (Alpine registration for remaining modules)

web/src/linking.ts

@@ -1,3 +1,5 @@
+import { showToast } from "./toast";
+
 async function loadUnlinkedBooks(): Promise<void> {
   const token = localStorage.getItem("token");
   if (!token) return;
@@ -91,21 +93,15 @@ async function linkBook(
     });
 
     if (response.ok) {
-      if ((window as any).showToast?.success) {
-        (window as any).showToast.success("Book linked successfully");
-      }
+      showToast("Book linked successfully", "success");
       loadUnlinkedBooks();
     } else {
       const error = await response.json();
-      if ((window as any).showToast?.error) {
-        (window as any).showToast.error(error.error || "Failed to link book");
-      }
+      showToast(error.error || "Failed to link book", "error");
     }
   } catch (error) {
     console.error("Failed to link book:", error);
-    if ((window as any).showToast?.error) {
-      (window as any).showToast.error("Failed to link book");
-    }
+    showToast("Failed to link book", "error");
   }
 }
 
@@ -127,18 +123,12 @@ async function autoLinkBooks(): Promise<void> {
 
     if (response.ok) {
       const data = await response.json();
-      if ((window as any).showToast?.success) {
-        (window as any).showToast.success(
-          `Auto-linked ${data.linked_count || 0} books`,
-        );
-      }
+      showToast(`Auto-linked ${data.linked_count || 0} books`, "success");
       loadUnlinkedBooks();
     }
   } catch (error) {
     console.error("Failed to auto-link:", error);
-    if ((window as any).showToast?.error) {
-      (window as any).showToast.error("Failed to auto-link books");
-    }
+    showToast("Failed to auto-link books", "error");
   }
 }