feat: 6 user-facing upgrades + realistic demo metrics + animated hero

Demo + assets
- Synthetic backtests now occasionally fail (regime failures, OOS degradation)
  so verdicts span RECOMMENDED / RISKY / NOT_RELIABLE realistically. Phase 1
  has ~35% failure rate, Phase 2 AI loop ~10%, OOS has 30% chance of severe
  degradation — matches what real markets look like
- screenshots/dashboard.png + best_result_modal.png regenerated against the
  current UI; screenshots/apex_demo.gif (6-frame autonomous-run timelapse)
  embedded in the README

FEATURE 1 — Live AI token streaming
- AIReasoner._call_claude() now streams via SSE when a callback is
  registered. Each text delta forwards to the dashboard as
  `ai_thinking_chunk` events
- The Live AI Thinking Feed renders a single growing bubble with a blinking
  cursor while text streams in, finalising on `end`. Looks and feels like
  watching the AI type

FEATURE 2 — Pre-flight check on /setup
- New /api/preflight endpoint runs 5–7 probes: config readable, API key
  set, MT5 paths exist (skipped in demo), EA registered, reports folder
  writable. Returns {ok, blocking_count, checks[]}
- Setup page renders a colour-coded checklist on load and refocus.
  Replaces "click Start, wait 5s, see generic error"

FEATURE 3 — Hot-reload settings into the running pipeline
- pipeline.reload_config() applies AI model / timeout / API-key swaps to
  the live reasoner mid-run. Threshold changes surface for next run
- /api/settings POST detects a running pipeline and calls reload_config(),
  returning the changed keys plus a "hot-reloaded into the running
  optimization" note

FEATURE 4 — Replay scrubber on Best Result
- Evolution path now renders as an interactive scrubber: range slider +
  prev/next/play buttons. Each step shows the run ID, phase, score, full
  metrics grid, parameter changes for that step, and the AI's analysis
  text — auto-plays at 700ms/step

FEATURE 5 — Compare runs on /reports
- Each card has a checkbox; selecting 2–4 reveals a floating Compare bar.
  Compare modal renders a side-by-side table with metric winners
  highlighted (Calmar / PF / profit favour higher; DD favours lower)
  and a parameter-diff section showing changed values

FEATURE 6 — Discord / Slack / generic webhook on completion
- New `notifications.webhook_url` + `webhook_style` config keys
- Auto-detects Discord vs Slack from the URL host. Posts a one-line
  summary on `optimization_complete`: verdict + best run + PF/Calmar/DD/
  profit/trades/elapsed

README.md

@@ -23,13 +23,13 @@ Calmar targets you set. Every reasoning step streams live to a dashboard.
 
 ## Demo
 
-![Dashboard](screenshots/dashboard.png)
+![APEX in action](screenshots/apex_demo.gif)
 
-The dashboard shows three live phases — **Exploration → Iteration → Validation** — with the
-AI's reasoning streaming on the right, parameter changes per iteration in the centre, and an
-out‑of‑sample/sensitivity validation panel that updates as MT5 finishes each test.
+> *6‑frame timelapse of one autonomous run — Phase 1 exploration → Phase 2 AI iteration → Phase 3 validation → verdict. Every backtest, every parameter change, and every line of AI reasoning streams live.*
 
-Other views: [setup wizard](screenshots/setup.png) · [settings modal](screenshots/settings_modal.png)
+A static high‑res view is at [`screenshots/dashboard.png`](screenshots/dashboard.png). The dashboard shows three live phases — **Exploration → Iteration → Validation** — with the AI's reasoning streaming on the right, parameter changes per iteration in the centre, and an out‑of‑sample/sensitivity validation panel that updates as MT5 finishes each test.
+
+Other views: [setup wizard](screenshots/setup.png) · [settings modal](screenshots/settings_modal.png) · [best‑result modal with evolution path](screenshots/best_result_modal.png)
 
 ---