docs: refresh screenshots and GIFs for current TUI

[yoelrosenthal]

Changes

• Regenerate all four screenshots and three GIFs from the current TUI, preserving the existing podcast examples and walkthroughs.
• Improve capture typography and connected box/block glyph rendering, including the updated banner.
• Capture live animation during pauses and retain existing README asset paths.

Verification

• cargo build --locked succeeded.
• Capture script completed all three walkthroughs with every state assertion passing.
• Visually inspected all four screenshots and complete GIF sequences.
• Verified all seven assets decode at 1572 × 1032, GIFs loop with valid durations, and README asset references resolve.
• git diff --check passed.

Captures use live RSS feeds and a disposable HOME; no audio was downloaded or user configuration changed.

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Summary by cubic

Refreshes README screenshots and GIFs so docs match the current TUI, and improves the capture script's rendering of box-drawing characters and live animation.

• Regenerates all four screenshots and three GIFs, keeping the existing podcast examples and asset paths.
• Adds custom glyph drawing for box-drawing, block-element, and slash characters so connected borders render correctly.
• Records frames every 100 ms during pauses so animations stay live instead of static holds.
• Requires DejaVu Sans and Sans Mono fonts (bold and oblique faces) plus the script's existing Python, Pillow, and pyte dependencies.
• Captures use live RSS feeds with a disposable HOME; no audio is downloaded and user configuration is untouched.

^{Written for commit 8ceec9e. Summary will update on new commits.}

Note

Refresh TUI documentation screenshots and GIFs via custom glyph renderer and time-sampled capture

• Regenerates all documentation screenshots and GIFs in docs/assets/ to match the current TUI
• Adds draw_glyph in capture_media.py to render box-drawing, block, and diagonal glyphs with explicit Pillow geometry, plus oblique font support for italic cells
• Changes Terminal.capture to sample terminal output every 100ms, merge consecutive identical frames, and accumulate adaptive-palette GIF frames with sampled durations instead of one static frame per call
• Switches terminal font from 18px to 17px DejaVu Sans Mono and adds the oblique face
• Risk: GIF frame timing and visual fidelity now depend on the new 100ms sampling loop and custom glyph renderer in capture_media.py; any unsupported Unicode glyph falls through to default rendering

^{Macroscope summarized b99ce6a.}

[cubic-dev-ai]

No issues found across 8 files

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