test: cover Textbox toolbar buttons and update test counts

fix: remove invalid Textbox clear button and tighten model/tokenizer types

chore: enable ruff UP (pyupgrade) ruleset

chore: upgrade dependencies to latest (hold transformers 4.x)

docs: use uv run in documented commands

docs: instruct use of /astral skills for Python tooling

chore: drop .superpowers/ ignore from .gitignore

chore: drop notebook ignore rules from .gitignore

chore: ignore Gradio flagged/ dir, drop stale docs/ ignore

docs: update CLAUDE.md test counts and setup commands

docs: update README for 418 languages and dev setup

chore: move dev dependencies to requirements-dev.txt

fix: address code review findings

docs: update CLAUDE.md for expanded language support

test: update app tests for symmetric dropdowns and swap button

feat: add symmetric language dropdowns with swap button

feat: update language mappings for new dict shape with region sorting

test: update langmap tests for expanded dict shape with regions

fix: add name spacing correction to generation script

feat: expand language mapping to 418 languages with regions

feat: add generation script for language mapping from MADLAD-400 paper

chore: add dev dependencies for language mapping generation

feat: update browser tab title to MADLAD-400 Translate

docs: rename project title to MADLAD-400 Translate

docs: update test counts in CLAUDE.md and README.md

test: add layout alignment tests and clean up blank lines

docs: update architecture for layout alignment changes

test: remove obsolete hint, char count, and button placement tests

feat: switch theme from Soft to Ocean

refactor: move translate button below both columns

refactor: remove hint and character count from UI

docs: update architecture description and test counts

fix: comma-format character count for consistency

fix: use Gradio CSS variables for info text styling

feat: move translate button into input column

refactor: move hint and char count from textbox info to gr.HTML element

docs: update architecture description for UI changes

feat: enforce 2000 character limit on input

refactor: extract _format_info helper for info string

feat: move hint and char count into input textbox info

docs: update README test counts

test: group UI tests by component

docs: clarify ty.toml comment for suppressed diagnostics

fix: use change event for char count to handle inline clear

docs: update architecture description for UI polish changes

docs: update test counts for UI polish changes

feat: add loading feedback on Translate button

feat: replace standalone Clear button with inline clear on input

feat: add character limit display and keyboard shortcut hint

feat: increase textbox height to 6 lines and remove input placeholder