fix(cli): kill resize scrollback duplication + light-mode visibility

Two long-standing prompt_toolkit bugs in the base hermes CLI:

1. Resize duplication. Column-shrink resize used to push 40+ rows of
   duplicate chrome (status bar, input rules) into terminal scrollback
   every resize. Same wall as pt issues #29 (open since 2014), #1675,
   #1933 — aider/xonsh/ipython all use alt-screen to dodge it.

   Root cause (verified by reading prompt_toolkit/renderer.py):
   _output_screen_diff (renderer.py L232-242) deliberately moves the
   cursor to the bottom of the canvas after every paint 'to make sure
   the terminal scrolls up'. In non-fullscreen mode this scrolls chrome
   content into terminal scrollback on every render — not just on
   resize.

   Fix: monkey-patch prompt_toolkit.renderer._output_screen_diff to
   bypass the reserve-vertical-space cursor move. When pt's logic checks
   'if current_height > previous_screen.height', we inflate the previous
   screen height so the branch falls through. ~30-line wrapper, no fork
   of pt, no alt-screen, no DECSTBM scroll region.

   Verified empirically in real Terminal.app: 10 resizes (mixed
   shrinks/widens 1300→500→1400) during streaming produced ZERO
   scrollback delta, full agent response preserved, status bar pinned
   at bottom, no visible duplicates. pt is pinned to ==3.0.52 so the
   private-function patch is safe; future pt bumps will need to
   re-verify the signature matches.

2. Light-mode terminal visibility. Hardcoded skin colors (#FFF8DC
   cornsilk, #FFD700 gold, #B8860B dark goldenrod) are tuned for dark
   Terminal.app — invisible on light/cream backgrounds.

   Port ui-tui/src/theme.ts detectLightMode() to Python so the base CLI
   adapts. Detection priority: HERMES_LIGHT/HERMES_TUI_LIGHT env →
   HERMES_TUI_THEME=light|dark → HERMES_TUI_BACKGROUND=#RRGGBB →
   COLORFGBG env (xterm/Konsole/urxvt) → OSC 11 query
   (\x1b]11;?\x1b\\) with 100ms timeout → default dark. OSC 11 is
   tty-gated so gateway/cron/batch/subagent code paths don't pay the
   timeout cost.

   When light mode is detected, dark-mode colors auto-remap to readable
   equivalents (#FFF8DC → #1A1A1A, #FFD700 → #9A6B00, etc). Hooked at
   three points:
   - _hex_to_ansi() — auto-remaps any color emitted via the ANSI helper
   - _build_tui_style_dict() — rewrites pt style strings (chrome bg/fg)
   - SkinConfig.get_color() — wrapped at module load so Rich Panel
     borders/body text get the remap too

   Status-bar foreground colors (#C0C0C0, #888888, etc.) are explicitly
   skipped because they're paired with a dark navy bg — remapping them
   would make them invisible in dark mode.

3. Other visibility fixes: [thinking] reasoning preview now uses ANSI
   dim+italic (\x1b[2;3m) instead of #B8860B so it inherits terminal
   default fg color. Input/prompt area defaults to terminal default fg
   (was #FFF8DC cornsilk → invisible on cream).

Co-authored-by: Brooklyn Nicholson <brooklyn.bb.nicholson@gmail.com>

hermes_cli/skin_engine.py

@@ -849,10 +849,14 @@ def get_prompt_toolkit_style_overrides() -> Dict[str, str]:
     except Exception:
         return {}
 
-    prompt = skin.get_color("prompt", "#FFF8DC")
+    # Input/prompt: leave unset by default so the typed text inherits
+    # the terminal's foreground color (readable in both light and dark
+    # color schemes).  Skins can opt into a colored prompt by setting
+    # `prompt` explicitly in their YAML.
+    prompt = skin.get_color("prompt", "")
     input_rule = skin.get_color("input_rule", "#CD7F32")
     title = skin.get_color("banner_title", "#FFD700")
-    text = skin.get_color("banner_text", prompt)
+    text = skin.get_color("banner_text", "#FFF8DC")
     dim = skin.get_color("banner_dim", "#555555")
     label = skin.get_color("ui_label", title)
     warn = skin.get_color("ui_warn", "#FF8C00")
@@ -872,7 +876,11 @@ def get_prompt_toolkit_style_overrides() -> Dict[str, str]:
     menu_meta_current_bg = skin.get_color("completion_menu_meta_current_bg", menu_current_bg)
 
     return {
-        "input-area": prompt,
+        # Typed input always uses terminal default fg/bg so it's
+        # readable in both light and dark Terminal.app modes.  The
+        # skin's `prompt` color (if any) only styles the prompt symbol,
+        # NOT the user's typed text.
+        "input-area": "",
         "placeholder": f"{dim} italic",
         "prompt": prompt,
         "prompt-working": f"{dim} italic",