fix(types): clear web/src type and lint debt with real types

tsc --noEmit and oxlint web/src are now both clean; vp check passes.

- htmx: one canonical Htmx interface in shims.d.ts (ajax/process/trigger
  per the htmx 2.x API). alpine.ts had a second, conflicting Window.htmx
  declaration (TS2717) — removed; bookPicker/collections lose their
  (window as any) escapes now that Window.htmx is properly typed.
- tsconfig lib ES2020 -> ES2021 + DOM.Iterable: replaceAll exists
  (escapeHtml) and for..of over querySelectorAll results is legal.
  Type-checking only — vite emits at esnext regardless.
- custom-section-builder: selectedBooks holds identity fields only;
  typed as Pick<BookInfo, ...> instead of forcing partial API shapes.
  The API-critical BookInfo contract is untouched.
- toast: real bug found by the type system — setup.ts passes 'warning'
  but getToastConfig had no entry, so the warning toast threw TypeError
  at runtime instead of displaying. Added the type + config. Uses
  bg-yellow-500 (verified present in scanned templates => generated by
  Tailwind); the one intentional behavior change in this commit.
- book-detail: instanceof narrowing replaces an as-cast; unused
  AnnotationSource import removed.
- password_validation: explicit HTMLElement | null for the checklist
  list (querySelector('ul') infers HTMLUListElement, conflicting with
  the container-as-list branch).
- stats: tooltip parsed value typed via annotation (bar=scalar,
  line={x,y}); dead getActiveRange() removed (was already tree-shaken
  out of every bundle).
- library-switcher: onSwitch honestly typed void | Promise<void>
  (series.ts passes a sync navigator).
- 20 unused catch bindings converted to optional catch binding.

Verification: fresh build is byte-reproducible; every chunk is
identical to the pre-fix build except main.js (instanceof narrowing,
regex fix, stats refactor), reader.js (destructure), and the shared
storage chunk (renamed — carries toast.ts). reader/main diffs audited
hunk-by-hunk against the intended edits.

web/src/reader/reader.ts

@@ -187,7 +187,7 @@ async function loadFontBlobUrls(): Promise<void> {
         const blob = await resp.blob();
         const blobUrl = URL.createObjectURL(blob);
         return { key: f.url, blobUrl };
-      } catch (_e) {
+      } catch {
         return { key: f.url, blobUrl: f.url };
       }
     }),
@@ -1533,7 +1533,7 @@ document.addEventListener("alpine:init", () => {
     async adjustFinalize() {
       const ctx = this.adjustContext;
       if (!ctx) return;
-      const { index, doc, range, id } = ctx;
+      const { index, range, id } = ctx;
       const text = range.toString().replace(/\s+/g, " ").trim();
       this.cancelAdjust();
       if (!text) {
@@ -2452,7 +2452,7 @@ document.addEventListener("alpine:init", () => {
             positionLabel: r.position ?? "",
           }));
         }
-      } catch (_e) {
+      } catch {
         /* annotations are non-critical; leave lists as-is */
       }
     },
@@ -2523,7 +2523,7 @@ document.addEventListener("alpine:init", () => {
           }
         }
         this.hideSelectionPopover();
-      } catch (_e) {
+      } catch {
         /* ignore highlight errors */
       }
     },
@@ -2590,7 +2590,7 @@ document.addEventListener("alpine:init", () => {
         // Explicit saves (the Save button) close the whole popover; color
         // tweaks made while the note editor is open keep everything open.
         if (!keepNoteOpen) this.hideSelectionPopover();
-      } catch (_e) {
+      } catch {
         /* ignore highlight errors */
       }
     },
@@ -2615,7 +2615,7 @@ document.addEventListener("alpine:init", () => {
           });
         }
         this.hideSelectionPopover();
-      } catch (_e) {
+      } catch {
         /* ignore highlight errors */
       }
     },
@@ -2839,7 +2839,7 @@ document.addEventListener("alpine:init", () => {
         });
         if (!resp.ok) return;
         await this.refreshAnnotations();
-      } catch (_e) {
+      } catch {
         /* ignore note errors */
       }
     },
@@ -2882,7 +2882,7 @@ document.addEventListener("alpine:init", () => {
         note.positionLabel = row.position ?? note.positionLabel;
         note.editOpen = false;
         note.editText = "";
-      } catch (_e) {
+      } catch {
         /* note errors are non-critical */
       }
     },
@@ -2897,7 +2897,7 @@ document.addEventListener("alpine:init", () => {
         if (resp.ok || resp.status === 204) {
           this.noteItems = this.noteItems.filter((n) => n.id !== id);
         }
-      } catch (_e) {
+      } catch {
         /* ignore note errors */
       }
     },
@@ -2928,7 +2928,7 @@ document.addEventListener("alpine:init", () => {
           page: typeof page === "number" ? page : 0,
           percentage: typeof pct === "number" ? pct : 0,
         };
-      } catch (_e) {
+      } catch {
         return {};
       }
     },
@@ -3017,7 +3017,7 @@ document.addEventListener("alpine:init", () => {
         });
         this.lastSyncedCfi = cfi || "";
         this.lastSyncedFraction = fraction;
-      } catch (_e) {
+      } catch {
         // silent fail — progress save is non-critical
       }
     },
@@ -3658,7 +3658,7 @@ document.addEventListener("alpine:init", () => {
           cfi: r.cfi_position?.String ?? r.cfi_position ?? "",
           page: r.page_number != null ? (r.page_number?.Int32 ?? r.page_number) : null,
         }));
-      } catch (_e) {
+      } catch {
         /* leave the existing list on fetch failure */
       }
     },
@@ -3696,7 +3696,7 @@ document.addEventListener("alpine:init", () => {
           await this.refreshBookmarks();
           showToast(`Bookmark added — ${this.progressText || "current position"}`, "success", 2500);
         }
-      } catch (_e) {
+      } catch {
         /* network failures surface via the toast fetch interceptor */
       }
     },
@@ -3711,7 +3711,7 @@ document.addEventListener("alpine:init", () => {
         if (resp.ok || resp.status === 204) {
           this.bookmarkItems = this.bookmarkItems.filter((b) => b.id !== id);
         }
-      } catch (_e) {
+      } catch {
         /* ignore bookmark errors for now */
       }
     },
@@ -3740,7 +3740,7 @@ document.addEventListener("alpine:init", () => {
           bookmark.title = title;
         }
         bookmark.renameOpen = false;
-      } catch (_e) {
+      } catch {
         bookmark.renameOpen = false;
       }
     },
@@ -3905,7 +3905,7 @@ document.addEventListener("alpine:init", () => {
           const data = await resp.json();
           this.readingSpeedPpm = data.pages_per_minute || 0;
         }
-      } catch (_e) {
+      } catch {
         this.readingSpeedPpm = 0;
       }
     },

web/src/reader/settings-manager.ts

@@ -16,7 +16,7 @@ export async function loadSettings(): Promise<ReaderSettings> {
     const settings = await response.json();
     localStorage.setItem(LOCALSTORAGE_KEY, JSON.stringify(settings));
     return settings;
-  } catch (error) {
+  } catch {
     const local = localStorage.getItem(LOCALSTORAGE_KEY);
     return local ? JSON.parse(local) : getDefaultSettings();
   }
@@ -39,7 +39,7 @@ export async function saveSettings(settings: Partial<ReaderSettings>): Promise<v
       body: JSON.stringify(settings),
     });
     localStorage.setItem(LOCALSTORAGE_KEY, JSON.stringify(updated));
-  } catch (error) {
+  } catch {
     localStorage.setItem(LOCALSTORAGE_KEY, JSON.stringify(updated));
   }
 }