refactor(reader): rewrite reader module for foliate-js pan/zoom integration

Major rewrite of the web reader to properly interface with
@bookhoard/foliate-js, replacing the abandoned panel-detection
architecture with direct pan and zoom support built into the
foliate-js FixedLayout renderer.

Template (reader.templ):
- Fix critical bug: x-init config was using literal strings
  '{ readerData.X }' inside a quoted attribute, which templ
  treated as raw text and never interpolated. Values were never
  actually passed to JavaScript. Now uses fmt.Sprintf() with
  templ's expression attribute syntax ={ }.
- Pass fileUrl from server so foliate-js can open books directly.
- Redesign bottom bar with foliate-js parity: left/right navigation
  buttons, progress slider with tick marks, and zoom controls
  (zoom out, percentage display, zoom in, magnifier, pan/select
  mode toggle for PDFs).
- Remove panel editor button and enablePanelDetection config.
- Add SVG icon styles for consistent reader controls.

Go types (templates/types.go):
- Expand ReaderMetadata with FormatGroup, MangaType,
  ReadingDirection, FileURL, and LibraryID fields needed by
  the reader frontend.

Router (internal/router/reader.go):
- Populate new ReaderMetadata fields from database values.
- Construct FileURL from library ID and file path for the
  /uploads/library-{id}/* file serving route.

Reader JS (reader.ts):
- Full rewrite modeled on foliate-js Reader class, adapted for
  Alpine.js. Opens books via view.open(fileUrl), accesses
  view.renderer for zoom/pan/navigation, and wires up keyboard
  shortcuts (+/-/0 for zoom, arrows for nav, Escape for magnifier).
- Uses view.isFixedLayout instead of importing FixedLayout class,
  avoiding a TypeScript module resolution issue with the Vite alias.

Settings manager (settings-manager.ts):
- Remove dependency on deleted ReaderContext event bus.
- Export loadSettings/saveSettings/syncSettings directly as
  standalone async functions.

Cleanup:
- Delete reader-context.ts and reader-events.ts (over-engineered
  event system replaced by direct function calls).
- Remove panel_zoom_enabled from ReaderSettings type.

web/src/reader/settings-manager.ts

@@ -1,64 +1,12 @@
-// Per-user settings with localStorage fallback
-// Feature Registration Pattern implementation
-
-import type { ReaderContext } from "./core/reader-context";
 import { apiGet, apiPut } from "../api";
 import { getToken } from "../storage";
-
 const LOCALSTORAGE_KEY = "reader_settings_local";
-
-export function init(context: ReaderContext): void {
-  let currentSettings: ReaderSettings | null = null;
-
-  context.events.on("reader:init", async () => {
-    currentSettings = await loadSettings();
-    context.events.emit("settings:loaded", currentSettings);
-  });
-
-  context.events.on(
-    "settings:save",
-    async (detail: { settings: Partial<ReaderSettings> }) => {
-      await saveSettings(detail.settings);
-      currentSettings = await loadSettings();
-      context.events.emit("settings:changed", currentSettings);
-    },
-  );
-
-  context.events.on(
-    "settings:get",
-    (detail: { key?: keyof ReaderSettings }) => {
-      if (currentSettings) {
-        const value = detail.key
-          ? currentSettings[detail.key]
-          : currentSettings;
-        context.events.emit("settings:current", { value });
-      }
-    },
-  );
-
-  context.events.on(
-    "settings:set",
-    async (detail: { key: keyof ReaderSettings; value: any }) => {
-      await saveSettings({ [detail.key]: detail.value });
-      currentSettings = await loadSettings();
-      context.events.emit("settings:changed", currentSettings);
-    },
-  );
-
-  context.events.on("settings:sync", async () => {
-    await syncSettings();
-    currentSettings = await loadSettings();
-    context.events.emit("settings:synced", currentSettings);
-  });
-}
-
 export async function loadSettings(): Promise<ReaderSettings> {
   const token = getToken();
   if (!token) {
     const local = localStorage.getItem(LOCALSTORAGE_KEY);
     return local ? JSON.parse(local) : getDefaultSettings();
   }
-
   try {
     const response = await apiGet("/readers/settings");
     const settings = await response.json();
@@ -69,17 +17,16 @@ export async function loadSettings(): Promise<ReaderSettings> {
     return local ? JSON.parse(local) : getDefaultSettings();
   }
 }
-
-async function saveSettings(settings: Partial<ReaderSettings>): Promise<void> {
+export async function saveSettings(
+  settings: Partial<ReaderSettings>,
+): Promise<void> {
   const token = getToken();
   const current = await loadSettings();
   const updated = { ...current, ...settings };
-
   if (!token) {
     localStorage.setItem(LOCALSTORAGE_KEY, JSON.stringify(updated));
     return;
   }
-
   try {
     await apiPut("/readers/settings", settings);
     localStorage.setItem(LOCALSTORAGE_KEY, JSON.stringify(updated));
@@ -87,14 +34,11 @@ async function saveSettings(settings: Partial<ReaderSettings>): Promise<void> {
     localStorage.setItem(LOCALSTORAGE_KEY, JSON.stringify(updated));
   }
 }
-
-async function syncSettings(): Promise<void> {
+export async function syncSettings(): Promise<void> {
   const local = localStorage.getItem(LOCALSTORAGE_KEY);
   if (!local) return;
-
   const settings = JSON.parse(local);
   const token = getToken();
-
   if (token) {
     try {
       await apiPut("/readers/settings", settings);
@@ -103,7 +47,6 @@ async function syncSettings(): Promise<void> {
     }
   }
 }
-
 export function getDefaultSettings(): ReaderSettings {
   return {
     chrome_behavior: "auto-hide",
@@ -113,7 +56,6 @@ export function getDefaultSettings(): ReaderSettings {
     reading_font: "literata",
     tap_zone_size: 30,
     auto_scroll: false,
-    panel_zoom_enabled: true,
     font_size: 16,
     line_height: 1.6,
     margin_width: 20,