docs(readme): unify banner family — hairline frame + single hero visual

Apply the cohesive banner pattern established for the Codechu
family:

  ━━━ c o d e c h u  ·  <name> ━━━

  [domain-specific hero content, the SOLE visual]

  ━━━ <tagline> ━━━

Removes the inconsistency where some READMEs carried a banner AT
THE TOP plus a second ASCII demo block IN THE BODY (or none at all,
depending on the lib). The banner now IS the hero — body has prose,
code, and capability bullets only. No second visual.

The richest demo per lib lives in the banner (combined where it
used to be split between top and body).

Author: obarlik

README.md

@@ -1,9 +1,14 @@
 ```text
-   ┌─[ codechu-cli ]──────────────────────────────────┐
-   │ $ deploy --prod                                  │
-   │ ⠿ building ......... [██████████▌      ]  68%    │
-   │ ? continue? [Y/n] ▏                              │
-   └──────────────────────────────────────────────────┘
+━━━━━━━━━━━━ c o d e c h u  ·  c l i ━━━━━━━━━━━━
+
+   $ deploy --prod
+   ? Deploy to production? [Y/n] y
+   deploy
+   [12 of 24 · 50% · 1m 32s · 156 items/s]  ████████████░░░░░░░░░░░░  ⠼
+     ↳ migrating database…                                            ✓
+     ↳ rolling out workers                                            ⠿
+
+━━━ colors · progress · spinners · prompts · tables ━━━
 ```
 
 [![PyPI](https://img.shields.io/pypi/v/codechu-cli.svg)](https://pypi.org/project/codechu-cli/)
@@ -19,13 +24,6 @@ Line-oriented CLI primitives for Python: colors, progress bars,
 spinners, prompts, tables, boxes. Consistent UX across every Codechu
 tool, with graceful fallbacks for pipes, Windows, and CI.
 
-```text
-deploy
-[12 of 24 · 50% · 1m 32s · 156 items/s]  ████████████░░░░░░░░░░░░  ⠼
-  ↳ migrating database…                                            ✓
-  ↳ rolling out workers                                            ⠿
-```
-
 ## Install
 
 ```bash