feat(dashboard): add 'default-large' built-in theme with 18px base size (#20820)

Same Hermes Teal palette as the default theme, but with baseSize 18px,
lineHeight 1.65, and spacious density so the whole dashboard scales up.
Gives users a one-click bigger-text preset and a copyable reference for
authoring custom YAML themes with their own typography settings.

hermes_cli/web_server.py

@@ -3260,8 +3260,9 @@ def mount_spa(application: FastAPI):
 # Built-in dashboard themes — label + description only.  The actual color
 # definitions live in the frontend (web/src/themes/presets.ts).
 _BUILTIN_DASHBOARD_THEMES = [
-    {"name": "default",   "label": "Hermes Teal",  "description": "Classic dark teal — the canonical Hermes look"},
-    {"name": "midnight",  "label": "Midnight",      "description": "Deep blue-violet with cool accents"},
+    {"name": "default",       "label": "Hermes Teal",         "description": "Classic dark teal — the canonical Hermes look"},
+    {"name": "default-large", "label": "Hermes Teal (Large)", "description": "Hermes Teal with bigger fonts and roomier spacing"},
+    {"name": "midnight",      "label": "Midnight",            "description": "Deep blue-violet with cool accents"},
     {"name": "ember",     "label": "Ember",          "description": "Warm crimson and bronze — forge vibes"},
     {"name": "mono",      "label": "Mono",           "description": "Clean grayscale — minimal and focused"},
     {"name": "cyberpunk", "label": "Cyberpunk",      "description": "Neon green on black — matrix terminal"},

web/src/themes/presets.ts

@@ -183,8 +183,30 @@ export const roseTheme: DashboardTheme = {
   },
 };
 
+/**
+ * Same look as ``defaultTheme`` but with a larger root font size, looser
+ * line-height, and ``spacious`` density so every rem-based size in the
+ * dashboard scales up. For users who find the default 15px UI too dense.
+ */
+export const defaultLargeTheme: DashboardTheme = {
+  name: "default-large",
+  label: "Hermes Teal (Large)",
+  description: "Hermes Teal with bigger fonts and roomier spacing",
+  palette: defaultTheme.palette,
+  typography: {
+    ...DEFAULT_TYPOGRAPHY,
+    baseSize: "18px",
+    lineHeight: "1.65",
+  },
+  layout: {
+    ...DEFAULT_LAYOUT,
+    density: "spacious",
+  },
+};
+
 export const BUILTIN_THEMES: Record<string, DashboardTheme> = {
   default: defaultTheme,
+  "default-large": defaultLargeTheme,
   midnight: midnightTheme,
   ember: emberTheme,
   mono: monoTheme,

website/docs/user-guide/features/extending-the-dashboard.md

@@ -265,6 +265,7 @@ Each built-in ships its own palette, typography, and layout — switching produc
 | Theme | Palette | Typography | Layout |
 |-------|---------|------------|--------|
 | **Hermes Teal** (`default`) | Dark teal + cream | System stack, 15px | 0.5rem radius, comfortable |
+| **Hermes Teal (Large)** (`default-large`) | Same as default | System stack, 18px, line-height 1.65 | 0.5rem radius, spacious |
 | **Midnight** (`midnight`) | Deep blue-violet | Inter + JetBrains Mono, 14px | 0.75rem radius, comfortable |
 | **Ember** (`ember`) | Warm crimson + bronze | Spectral (serif) + IBM Plex Mono, 15px | 0.25rem radius, comfortable |
 | **Mono** (`mono`) | Grayscale | IBM Plex Sans + IBM Plex Mono, 13px | 0 radius, compact |

website/docs/user-guide/features/web-dashboard.md

@@ -334,6 +334,7 @@ Built-in themes:
 | Theme | Character |
 |-------|-----------|
 | **Hermes Teal** (`default`) | Dark teal + cream, system fonts, comfortable spacing |
+| **Hermes Teal (Large)** (`default-large`) | Same as default with 18px text and roomier spacing |
 | **Midnight** (`midnight`) | Deep blue-violet, Inter + JetBrains Mono |
 | **Ember** (`ember`) | Warm crimson + bronze, Spectral serif + IBM Plex Mono |
 | **Mono** (`mono`) | Grayscale, IBM Plex, compact |