refactor(settings): redesign BotConfigPanel + fix paper mode + clarify all copy

BotConfigPanel (full rewrite, 1113→858 lines):
- Remove 3-tab layout; replace with two expandable cards (Trump Signal /
  Macro Vibes) + collapsed Advanced block — fewer decisions, less noise
- Fix paper mode bug: UserResponse now returns paper_mode; BotConfigPanel
  tracks it in state; missingItems skips HL key requirement for paper users;
  HL key card shows paper status instead of empty input
- Add "Switch to live →" upgrade path — calls /subscribe with paper_mode=false
  so paper users can promote without re-subscribing from scratch
- Add confirmSign before manual override window (consistent with all other
  mutations); rename "Arm/Disarm" → "Override/Cancel override" throughout
- Fix all ambiguous copy: subscribe card, Macro Vibes description (manual
  /adopt flow, not auto-manage), missingItems strings, TP/SL "Not saved yet"
  → "Required — not saved", "Daily spend cap" → "Daily trading cap",
  "Active schedule" → "Trading schedule", "Get started" confirmSign labels

lib/api.ts:
- Add paper_mode: boolean to UserData interface (was missing)

OpenPositions:
- "Load your settings once…" → "Sign in once to view open positions" (removes
  implementation-detail explanation)
- "Today realised" → "Today's realized"; "banked" → "locked in" throughout
- "The bot will appear here" → "When the bot opens a trade, it will show up here"

SystemControl:
- "Net result" → "Current status"

settings/SettingsClient.tsx:
- id="btc-settings" → id="macro-settings" (stale rename)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

components/signals/SystemControl.tsx

@@ -126,7 +126,7 @@ export default function SystemControl({ system }: { system: 'trump' | 'btc' }) {
   // wagmi state that resolves client-side.
   if (!mounted) return null
 
-  const settingsHref = `/${locale}/settings#${system === 'trump' ? 'trump-settings-panel' : 'btc-settings-panel'}`
+  const settingsHref = `/${locale}/settings#bot-config`
   const settingsLabel = system === 'trump' ? 'Trump Signal' : 'Macro Vibes'
 
   // Wallet not connected: a previous version showed a giant full-width
@@ -298,7 +298,7 @@ export default function SystemControl({ system }: { system: 'trump' | 'btc' }) {
       }}>
         <div style={{ fontSize: 11, fontWeight: 700, letterSpacing: '.06em',
                       textTransform: 'uppercase', color: 'var(--ink-3)', marginBottom: 4 }}>
-          {isZh ? '⟹ 当前结果' : '⟹ Net result'}
+          {isZh ? '⟹ 当前状态' : '⟹ Current status'}
         </div>
         <div style={{ fontSize: 14, fontWeight: 700,
                       color: netOk ? 'var(--up)' : 'var(--down)' }}>