fix(electrobun): fix PathBrowser process.env.HOME, add dual browse buttons

- PathBrowser: resolveHome() via files.homeDir RPC (was process.env.HOME)
- ProjectWizard: two browse buttons — 📂 native dialog + 🔍 in-app browser
- In-app browser uses display toggle (rule 55), dirs-only filter
- Native dialog: Electrobun Utils.openFileDialog (GTK chooser)
- In-app browser: themed, dirs sorted first, proper breadcrumbs

ui-electrobun/src/mainview/ProjectWizard.svelte

@@ -293,13 +293,20 @@
               bind:value={localPath}
               oninput={() => validatePath(localPath)} />
             <button class="wz-browse-btn" onclick={handleNativeBrowse}
+              title="Open system folder picker"
               aria-label={t('wizard.step1.browse' as any)}>📂</button>
+            <button class="wz-browse-btn" onclick={() => showBrowser = !showBrowser}
+              title="In-app folder browser"
+              aria-label="Browse">🔍</button>
             {#if pathValid !== 'idle'}
               <span class="wz-validation" style:color={validationColor(pathValid)}>
                 {validationIcon(pathValid)}
               </span>
             {/if}
           </div>
+          <div style:display={showBrowser ? 'block' : 'none'}>
+            <PathBrowser onSelect={handleBrowserSelect} onClose={() => showBrowser = false} />
+          </div>
           {#if pathValid === 'valid' && isGitRepo}
             <span class="wz-badge git-badge">{t('wizard.step1.gitDetected' as any)} ({gitBranch})</span>
           {/if}