feat(ux): B3.6 — editable energy labels (global + per-profile) + first-tap prompt

Settings → Energy: edit global energy labels (label + description per
level) with reset-to-defaults. Per-profile override toggle in the
Profiles section ("Customise for this profile" / "Use global").
EnergyChip and Tasks-page energy controls now resolve labels via
resolveEnergyLabels(profile, settings) — global by default, profile
override when present.

First-time prompt: on first energy-chip tap of the day (per profile)
or first-ever tap to Zero, an inline non-modal prompt asks "What does
Zero mean for you today?" with example chips. Per-day gate via
energyPromptLastShownDate; one-shot first-Zero gate via
energyPromptZeroSeen; Settings escape resets both.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/stores/page.svelte.ts

@@ -41,6 +41,20 @@ const PROFILES_KEY = "kon_profiles";
 const TASK_LISTS_KEY = "kon_task_lists";
 const TEMPLATES_KEY = "kon_templates";
 
+/**
+ * B3.6 — exported energy-label defaults so the Settings "Reset to
+ * defaults" button can pull them without reaching into the private
+ * `defaults` block. Returns a fresh object on each call so callers
+ * cannot mutate the source-of-truth.
+ */
+export function defaultEnergyLabels(): SettingsState["energyLabels"] {
+  return {
+    high: { label: "High", description: "Sharp focus, big lifts" },
+    medium: { label: "Medium", description: "Steady work, moderate lifts" },
+    brain_dead: { label: "Zero", description: "Rest only, low-touch admin" },
+  };
+}
+
 const defaults: SettingsState = {
   engine: "whisper",
   modelSize: "Base",
@@ -97,11 +111,13 @@ const defaults: SettingsState = {
   sparklineRangeDays: 7,
   // Defaults mirror current EnergyChip copy so existing behaviour is
   // unchanged until the user edits via the (B3.6) UI.
-  energyLabels: {
-    high: { label: "High", description: "Sharp focus, big lifts" },
-    medium: { label: "Medium", description: "Steady work, moderate lifts" },
-    brain_dead: { label: "Zero", description: "Rest only, low-touch admin" },
-  },
+  energyLabels: defaultEnergyLabels(),
+  // B3.6 — first-tap energy-prompt gates. Default ON for prompts;
+  // never-shown date stamp; first-Zero one-shot unfired. The merge in
+  // loadSettings will fill these on existing installs as well.
+  energyPromptsEnabled: true,
+  energyPromptLastShownDate: null,
+  energyPromptZeroSeen: false,
 };
 
 function canUseStorage(): boolean {