Update .editorconfig and bump dev dependencies

[coliff]

Rework .editorconfig ordering and add file-specific rules for minified files, SVGs and CNAME; enable insert_final_newline and trim_trailing_whitespace by default. Update package.json and package-lock.json (including website/) to bump numerous dev dependencies and transitive packages — notable bumps include Jest (30.2.0 → 30.3.0), many @babel packages (to 7.28.x/7.29.x), @sinonjs/fake-timers, @emnapi, and @sinclair/typebox. These are routine minor/patch updates to address bugs, security notices and keep the toolchain current.

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[Copilot]

Pull request overview

This PR updates repository-wide editing defaults and refreshes the JavaScript toolchain by bumping several development dependencies (including Jest and Astro/Starlight for the website). It also consolidates agent/instructions documentation by relocating content into AGENTS.md and .github/AGENTS.md.

Changes:

• Rework .editorconfig and add file-specific newline rules for minified files, SVGs, and CNAME.
• Bump dev dependencies in the root package and website (Astro/Starlight, Jest, and many transitive packages via lockfile updates).
• Restructure/relocate agent instruction docs (add AGENTS.md content, remove old Copilot/Cursor/Gemini config files).

Reviewed changes

Copilot reviewed 8 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
website/package.json	Updates Astro/Starlight versions and tightens Node engine/Volta pin for the website.
website/package-lock.json	Lockfile refresh to match updated website dependencies.
package.json	Bumps Jest version in root devDependencies.
package-lock.json	Lockfile refresh to match updated root dependency graph (Jest + transitive updates).
AGENTS.md	Adds consolidated repo guidance and documentation conventions.
.github/copilot-instructions.md	Removes legacy Copilot instruction file (content moved elsewhere).
.github/AGENTS.md	Adds GitHub Actions/Dependabot guidance under .github/.
.gemini/config.yaml	Removes Gemini configuration file.
.editorconfig	Reorders/adjusts global defaults and adds per-pattern newline exceptions.
.cursor/rules/general.mdc	Removes Cursor rules file (content moved elsewhere).

Files not reviewed (1)

• website/package-lock.json: Language not supported

[gemini-code-assist]

Code Review

The pull request updates dependencies in package-lock.json and website/package-lock.json, including @babel/core, jest, @sinclair/typebox, @sinonjs/fake-timers, caniuse-lite, ci-info, glob, jest-diff-sequences, jest-environment, jest-expect, jest-expect-utils, jest-fake-timers, jest-globals, jest-reporters, jest-snapshot-utils, jest-test-result, jest-test-sequencer, jest-transform, jest-types, jest-util, jest-validate, jest-watcher, jest-cli, jest-config, jest-haste-map, jest-leak-detector, jest-matcher-utils, jest-message-util, jest-mock, jest-resolve, jest-resolve-dependencies, jest-runner, jest-runtime, jest-snapshot, babel-jest, babel-plugin-jest-hoist, babel-preset-jest, baseline-browser-mapping, browserslist, electron-to-chromium, h3, hashery, qified, rollup, stylelint, flat-cache, and node-releases. It also updates the Astro Starlight version in website/package.json.