feat(FN-1739): merge fusion/fn-1739

.fusion/memory.md

@@ -260,6 +260,7 @@ Dashboard SSE (`/api/events`) streams plugin lifecycle events as normalized `plu
 - `mission-store.test.ts` has a flaky test (`getMissionHealth computes mission metrics and latest error context`) that fails intermittently when timestamps collide in the same millisecond — this is pre-existing and not related to dashboard changes.
 - **SettingsModal sidebar reordering**: When reordering sections in `SETTINGS_SECTIONS`, update all tests that assume a specific section is the default. Tests using `screen.getByText("SectionName")` may fail with "multiple elements found" when the section heading also appears in the content area alongside the sidebar item. Use `screen.getAllByText("SectionName")[0]` or navigate to the section explicitly before accessing its fields.
 - **Test isolation with temp directories**: Tests that create filesystem state (like agent files under `.fusion/agents/`) should use per-test temp directories via `mkdtempSync(join(os.tmpdir(), 'fn-test-'))` and clean up in `afterEach` with `rmSync(dir, { recursive: true, force: true })`. Shared temp paths cause state leakage between tests, leading to noisy/flaky behavior. See `in-process-runtime.test.ts` for the pattern.
+- **xterm.js WebGL on mobile (FN-1739)**: The `@xterm/addon-webgl` addon causes garbled/overlapping Unicode text on mobile browsers (especially iOS Safari/WebKit) due to rendering artifacts. Always wrap WebGL addon loading in a `!isMobileDevice()` check, falling back to canvas rendering for mobile. Use the project's monospace font stack (`ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace`) for better Unicode coverage on all platforms.
 
 - When adding light-theme overrides for CSS components that already use `var(--*)` tokens, most selectors inherit correctly from the light-theme root variable redefinitions. Only add explicit `[data-theme="light"]` overrides where fine-tuning is needed (e.g., slightly different opacity values, subtle box-shadows for contrast).
 - `--surface-hover` is used but never defined as a CSS custom property in the root or light theme blocks — it resolves to invalid/empty. Components using `var(--surface-hover)` (like `.github-import-tab:hover`) get no background. Either define it in the theme roots or use fallbacks like `var(--surface-hover, rgba(0,0,0,0.03))`.