chore: remove obsolete rules files (consolidated into 53/54 sequence)

.claude/rules/18-relative-units.md

@@ -1,17 +0,0 @@
-# Relative Units (CSS)
-
-Use relative units (`em`, `rem`, `%`, `vh`, `vw`) for layout and spacing. Pixels are acceptable only for:
-
-- Icon sizes (`width`/`height` on `<svg>` or icon containers)
-- Borders and outlines (`1px solid ...`)
-- Box shadows
-
-## Rules
-
-- **Layout dimensions** (width, height, max-width, min-width): use `em`, `rem`, `%`, or viewport units.
-- **Padding and margin**: use `em` or `rem`.
-- **Font sizes**: use `rem` or `em`, never `px`.
-- **Gap, border-radius**: use `em` or `rem`.
-- **Media queries**: use `em`.
-- When existing code uses `px` for layout elements, convert to relative units as part of the change.
-- CSS custom properties for typography (`--ui-font-size`, `--term-font-size`) store `px` values because they feed into JS APIs (xterm.js) that require pixels. This is the only exception beyond icons/borders.

.claude/rules/20-testing-gate.md

@@ -1,32 +0,0 @@
-# Testing Gate (Post-Implementation)
-
-Run the full test suite after every major change before considering work complete.
-
-## What Counts as a Major Change
-
-- New feature or component
-- Refactoring that touches 3+ files
-- Store, adapter, or bridge modifications
-- Rust backend changes (commands, SQLite, sidecar)
-- Build or CI configuration changes
-
-## Required Command
-
-```bash
-cd v2 && npm run test:all
-```
-
-This runs vitest (frontend) + cargo test (backend). For changes touching E2E-relevant UI or interaction flows, also run:
-
-```bash
-cd v2 && npm run test:all:e2e
-```
-
-## Rules
-
-- Do NOT skip tests to save time. A broken test suite is a blocking issue.
-- If tests fail, fix them before moving on. Do not defer test fixes to a follow-up.
-- If a change breaks existing tests, that's signal — investigate whether the change or the test is wrong.
-- When adding new logic, add tests in the same commit (TDD preferred, see rule 06).
-- After fixing test failures, re-run the full suite to confirm no cascading breakage.
-- Report test results to the user: pass count, fail count, skip count.