fix(search,excalidraw,e2e): recherche cassee + corruption .excalidraw.md + tests E2E #78

- frontend/js/search.js : onSearchFilter appelee avec (vault, query, results) — renvoyait undefined, cassait le rendu et basculait sur la recherche offline (0 resultat). Regression plugins depuis 30f2df3.
- frontend/excalidraw-editor.html + js/excalidraw-viewer.js : ignorer onChange au montage (plus d'auto-save spurieux qui reecrivait .excalidraw.md en JSON brut) + preservation du format Obsidian frontmatter + compressed-json a la sauvegarde.
- frontend/js/app.js : __OBSIGATE_BOOTED pose apres init() (splash + E2E attendent les handlers lies).
- tests/e2e : goHome/login attendent le boot ; excalidraw.spec.js reecrit avec les selecteurs reels (modal, context menu, canvas.first()).
- ROADMAP : C8 (creation via menu contextuel) marque fait.
- Verifie : 86/86 E2E chromium-desktop, 599 backend, ruff, validate-imports, JSDOM.

frontend/excalidraw-editor.html

@@ -102,7 +102,7 @@
   <script type="module">
     import React from "https://esm.sh/react@^19.2.0?target=es2022";
     import { createRoot } from "https://esm.sh/react-dom@^19.2.0/client?target=es2022";
-    import { decompressFromBase64 } from "https://esm.sh/[email protected]";
+    import { decompressFromBase64, compressToBase64 } from "https://esm.sh/[email protected]";
     import * as ExcalidrawLib from "https://esm.sh/@excalidraw/[email protected]";
 
     window.React = React;
@@ -116,6 +116,12 @@
     let isDirty = false;
     let currentTheme = "light";
     let saveTimeout = null;
+    // Excalidraw fires onChange on initial mount; ignore those so simply
+    // opening a diagram does not trigger a spurious autosave (which would
+    // rewrite a .excalidraw.md file as raw JSON and destroy its format).
+    let ignoreChanges = true;
+    // Source format: "md" for the Obsidian .excalidraw.md (compressed-json).
+    let sourceIsMd = false;
 
     // --- DOM refs ---
     const loadingEl = document.getElementById("loading");
@@ -153,16 +159,23 @@
       const elements = excalidrawAPI.getSceneElements();
       const appState = excalidrawAPI.getAppState();
       const files = excalidrawAPI.getFiles();
-      sendToParent({
-        type: "save",
-        data: {
-          type: "excalidraw",
-          version: 2,
-          elements: elements,
-          appState: appState,
-          files: files,
-        },
-      });
+      const data = {
+        type: "excalidraw",
+        version: 2,
+        elements: elements,
+        appState: appState,
+        files: files,
+      };
+      // Preserve the Obsidian .excalidraw.md format: ship the compressed
+      // scene so the parent can rewrite the frontmatter + compressed-json block.
+      if (sourceIsMd) {
+        try {
+          data.compressed = compressToBase64(JSON.stringify(data));
+        } catch (e) {
+          console.error("Failed to compress Excalidraw scene:", e);
+        }
+      }
+      sendToParent({ type: "save", data });
       markClean();
       btnSave.textContent = "💾 Saved!";
       setTimeout(() => { btnSave.textContent = "💾 Save"; }, 1200);
@@ -191,10 +204,13 @@
           if (theme === "dark") {
             api.updateScene({ appState: { theme: "dark" } });
           }
+          // Stop ignoring changes once the initial mount settles.
+          setTimeout(() => { ignoreChanges = false; }, 800);
         }
       }, [theme]);
 
       const onChange = React.useCallback((elements, state, files) => {
+        if (ignoreChanges) return;
         markDirty();
       }, []);
 
@@ -225,6 +241,7 @@
             let elements, appState, files;
             // Handle compressed .excalidraw.md format
             if (msg.data.compressed) {
+              sourceIsMd = true;
               try {
                 const decompressed = decompressFromBase64(msg.data.compressed);
                 const parsed = JSON.parse(decompressed);