docs: clean up Copilot customization guidance after #116

[GeekTrainer]

Description

Align the supplied customization documentation with the unit tests, lint, and type checks run by quality-checks after #116. Simplify the README by removing the customization overview and optional App Run Menu guidance. Clarify that package.json commands run Astro and TypeScript database setup tasks through npm.

Related Issue

Closes #125

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 📚 Documentation update
• 🧪 Test update
• 🔧 Refactor (no functional changes)

Changes Made

• Clarify quality-checks scope in its description, headings, policy, and checklist while preserving commands and troubleshooting.
• Remove the README's customization overview, including obsolete PR Readiness agent guidance and optional App Run Menu documentation.
• Align the Copilot instructions' skill references with all three check types while preserving separate frontend E2E requirements.
• Clarify npm commands and lifecycle hooks in the README, Copilot instructions, and quality-checks setup guidance: Astro handles the site; TypeScript tasks in db/ migrate and seed SQLite.

Testing

• git diff --check and tracked-file reference audit passed.
• Documentation assertions confirmed unchanged skill command blocks, preserved E2E requirements, valid unit-test guidance link, absence of the learner QA agent/Results solution, and exactly three changed documentation files.
• Via the quality-checks skill: 39 unit tests passed; ESLint passed; both type checks passed (Astro: zero errors, warnings, or hints).
• Static build and all 21 Playwright tests passed using a temporary external config on port 14321. The initial standard E2E invocation reused port 4321, which was serving another project; no existing server was stopped, and the repository test configuration was unchanged. The temporary config was removed.
• Subsequent documentation-only follow-ups passed whitespace and content assertions. The customization overview and App Run Menu section are removed; setup wording matches package.json, skill commands are preserved, and no stale links target the renamed instructions heading. Application checks above were run before these documentation-only follow-ups.

Data Layer Changes

N/A — documentation only.

• Ran npm run test:unit - all tests pass
• Added/updated Vitest tests for data-layer changes
• Generated a migration (npm run db:generate) for any schema change

Frontend Changes

N/A — documentation only; build and E2E checks were still run as contribution checks.

• Ran npm run test:e2e - all tests pass
• Added data-testid attributes to interactive elements
• Verified build succeeds (npm run build)

Checklist

• My code follows the project's coding standards
• I have used explicit TypeScript types for function parameters and return values
• I have built the UI with Astro components and Tailwind CSS utility classes (dark theme)
• I have updated documentation (README, instruction files) if needed
• My changes are focused on a single concern
• I have written clear commit messages explaining what and why

The unchecked implementation items are not applicable to this documentation-only change.

Additional Notes

Based on main at f63522393e8b5ebe0b6e86b0c11398ee98da1b2b, including #116. The Results-formatting and QA-profile exercises remain for learners. Application code, package.json, devcontainer and app configuration, CI, E2E tests, Playwright instructions, and the Database Explorer extension remain unchanged. No software was installed.

[Copilot]

Copilot review overview

🟢 Approval recommended

The documentation changes consistently satisfy issue #125 without altering commands or E2E requirements.

Review effort: Balanced
Findings: None

What changed in this PR

Aligns Copilot documentation with the current quality-check workflow and removes obsolete agent guidance.

Changes:

• Documents unit tests, lint, and type checks as skill-managed.
• Preserves direct Playwright E2E guidance.
• Removes the deleted PR Readiness agent section.

File	Description
README.md	Updates customization and skill documentation.
.github/​skills/​quality-checks/​SKILL.md	Clarifies supported checks and policies.
.github/​copilot-instructions.md	Aligns contributor verification guidance.

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