feat(reskin): customize auth/login surfaces to Cortex aesthetic

Customize Warp's authentication / login surfaces (three canonical views
+ the 7-slide agent onboarding deck) to match Cortex's aesthetic.
Mapped in docs/investigations/auth-onboarding-three-views.md.

Auth view changes:

- View #1 (IntroSlide, `crates/onboarding/src/slides/intro_slide.rs`):
  swap CORTEX ASCII to `figlet ansi_shadow`, brain glyph on top (35%
  smaller at 146pt), centered title/brain column, outline-pink CTA
  buttons that invert on hover (`CortexPinkOutline` button theme),
  "Powered by Warp" credit under the title, Cortex version chip in
  the top-left corner.

- View warpdotdev#2 (LoginSlideView, `app/src/auth/login_slide.rs`): all three
  sub-screens (SelectAuthPathway, BrowserOpen, PrivacySettings)
  routed through Cortex-specific centered single-column helpers;
  upstream two-column `layout::static_left + render_visual` path
  retired.

- View warpdotdev#3 (AuthView / AuthViewBody, `app/src/auth/auth_view_body.rs`):
  Initial-variant reskin with horizontal naked-pink-brain +
  Welcome-to/CORTEX-figlet header, centered "Powered by Warp" credit,
  and three vertically-stacked pink-outline CTA buttons (Sign up /
  Sign in / Skip for now) with hover-invert behavior. Texts rephrased
  to clarify these are Warp account actions ("Sign up for a Warp
  account" rather than just "Sign up"). Non-Initial
  Warp-Drive-share-boundary variants stay upstream-shaped.

Agent onboarding deck (6 slides — Intention, Customize, Agent,
ThirdParty, Project, ThemePicker): each slide's render method now
bypasses `layout::static_left` so the right-side Warp UI screenshot
disappears; content renders centered single-column.

Foundation:

- Removed `SKIP_WARP_ACCOUNT_LOGIN` const and dropped
  `skip_firebase_anonymous_user` from `app/Cargo.toml` default
  features so the login surface fires as the default product
  experience rather than being bypassed by the personal-use posture.

- New `crates/warp_core/src/cortex.rs` module hosts shared Cortex
  branding constants (`BRAIN_PINK`, `CORTEX_ASCII`). `Icon` enum
  gained a `WarpLogoWithLightTitle` variant mapped to the existing
  warp-logo-with-light-title.svg asset for the "Powered by Warp"
  wordmark rendering.

Dev launcher (`scripts/launch-cortex-dev.bat`) defaults to clearing
`HasCompletedOnboarding` on every launch so iteration on Views #1 / warpdotdev#2
surfaces them reliably; commented inline with the swap to flip into
AuthView (View warpdotdev#3) iteration mode.

Upstream-shaped helpers preserved with \`#[allow(dead_code)]\` for
merge clarity wherever the Cortex path supersedes them.

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

Author: lawsmd

app/Cargo.toml

@@ -632,7 +632,12 @@ default = [
     "codex_notifications",
     "trim_trailing_blank_lines",
     "open_warp_new_settings_modes",
-    "skip_firebase_anonymous_user",
+    # Cortex fork: intentionally omit "skip_firebase_anonymous_user".
+    # Upstream's default short-circuits the post-login-not-found path
+    # into "anonymous logged-out workspace" — that's Warp's stance, not
+    # ours. Cortex ships the warp-account login slide as real first-run
+    # product behavior (reskinned per docs/roadmap/reskin.md). Re-omit
+    # on every upstream merge.
     "settings_file",
     "directory_tab_colors",
     "configurable_context_window",

app/assets/cortex/ascii/CortexAscii5.txt

@@ -1,8 +1,7 @@
-   █████████     ███████    ███████████   ███████████ ██████████ █████ █████
-  ███░░░░░███  ███░░░░░███ ░░███░░░░░███ ░█░░░███░░░█░░███░░░░░█░░███ ░░███
- ███     ░░░  ███     ░░███ ░███    ░███ ░   ░███  ░  ░███  █ ░  ░░███ ███
-░███         ░███      ░███ ░██████████      ░███     ░██████     ░░█████
-░███         ░███      ░███ ░███░░░░░███     ░███     ░███░░█      ███░███
-░░███     ███░░███     ███  ░███    ░███     ░███     ░███ ░   █  ███ ░░███
- ░░█████████  ░░░███████░   █████   █████    █████    ██████████ █████ █████
-  ░░░░░░░░░     ░░░░░░░    ░░░░░   ░░░░░    ░░░░░    ░░░░░░░░░░ ░░░░░ ░░░░░
+ ██████╗ ██████╗ ██████╗ ████████╗███████╗██╗  ██╗
+██╔════╝██╔═══██╗██╔══██╗╚══██╔══╝██╔════╝╚██╗██╔╝
+██║     ██║   ██║██████╔╝   ██║   █████╗   ╚███╔╝ 
+██║     ██║   ██║██╔══██╗   ██║   ██╔══╝   ██╔██╗ 
+╚██████╗╚██████╔╝██║  ██║   ██║   ███████╗██╔╝ ██╗
+ ╚═════╝ ╚═════╝ ╚═╝  ╚═╝   ╚═╝   ╚══════╝╚═╝  ╚═╝
+