chore: add Claude Code settings and agent instructions (#15978)

Add project configuration for Claude Code AI assistant.

`.claude/settings.json` grants read-only permissions for common commands
(git, yarn, docker, make) and allows Sentry skills and documentation
domains. This enables Claude Code to explore the codebase without
prompting for every read operation.

`AGENTS.md` documents key project conventions: package manager (yarn),
development commands, project structure, and code style expectations.
`CLAUDE.md` symlinks to it for compatibility with different agent naming
conventions.

Author: dcramer

.claude/settings.json

@@ -0,0 +1,64 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(ls:*)",
+      "Bash(pwd:*)",
+      "Bash(find:*)",
+      "Bash(file:*)",
+      "Bash(stat:*)",
+      "Bash(wc:*)",
+      "Bash(head:*)",
+      "Bash(tail:*)",
+      "Bash(cat:*)",
+      "Bash(tree:*)",
+      "Bash(git status:*)",
+      "Bash(git log:*)",
+      "Bash(git diff:*)",
+      "Bash(git show:*)",
+      "Bash(git branch:*)",
+      "Bash(git remote:*)",
+      "Bash(git tag:*)",
+      "Bash(git stash list:*)",
+      "Bash(git rev-parse:*)",
+      "Bash(gh pr view:*)",
+      "Bash(gh pr list:*)",
+      "Bash(gh pr checks:*)",
+      "Bash(gh pr diff:*)",
+      "Bash(gh issue view:*)",
+      "Bash(gh issue list:*)",
+      "Bash(gh run view:*)",
+      "Bash(gh run list:*)",
+      "Bash(gh run logs:*)",
+      "Bash(gh repo view:*)",
+      "Bash(gh api:*)",
+      "Bash(node --version:*)",
+      "Bash(yarn list:*)",
+      "Bash(yarn info:*)",
+      "Bash(yarn why:*)",
+      "Bash(tsc --version:*)",
+      "Bash(docker --version:*)",
+      "Bash(docker ps:*)",
+      "Bash(docker images:*)",
+      "Bash(docker-compose ps:*)",
+      "Bash(docker-compose config:*)",
+      "Bash(make --version:*)",
+      "Bash(make -n:*)",
+      "Skill(sentry-skills:commit)",
+      "Skill(sentry-skills:create-pr)",
+      "Skill(sentry-skills:code-review)",
+      "Skill(sentry-skills:find-bugs)",
+      "Skill(sentry-skills:deslop)",
+      "Skill(sentry-skills:iterate-pr)",
+      "Skill(sentry-skills:claude-settings-audit)",
+      "Skill(sentry-skills:agents-md)",
+      "WebFetch(domain:docs.sentry.io)",
+      "WebFetch(domain:develop.sentry.dev)",
+      "WebFetch(domain:docs.github.com)",
+      "WebFetch(domain:cli.github.com)",
+      "WebFetch(domain:react.dev)",
+      "WebFetch(domain:nextjs.org)",
+      "WebFetch(domain:docs.docker.com)"
+    ],
+    "deny": []
+  }
+}

AGENTS.md

@@ -0,0 +1,52 @@
+# Agent Instructions
+
+## Package Manager
+Use **yarn**: `yarn install`, `yarn dev`, `yarn build`, `yarn test`
+
+## Commit Attribution
+AI commits MUST include:
+```
+Co-Authored-By: Claude <[email protected]>
+```
+
+## Development
+- `yarn dev` - Start dev server with Sentry sidecar
+- `yarn dev:minimal` - Start dev server without sidecar
+- `yarn build` - Production build
+- `yarn test` - Run tests with vitest
+- `yarn lint` - Run all linters
+- `yarn lint:fix` - Auto-fix lint issues
+
+## Tech Stack
+- Next.js 15 with App Router
+- React 19
+- TypeScript
+- Tailwind CSS
+- MDX for documentation content
+- Sentry SDK (`@sentry/nextjs`)
+
+## Project Structure
+- `app/` - Next.js app router pages and layouts
+- `src/` - Source code (components, utilities)
+- `docs/` - MDX documentation content
+- `develop-docs/` - Developer documentation (submodule)
+- `includes/` - Reusable MDX includes
+- `platform-includes/` - Platform-specific MDX content
+- `public/` - Static assets
+
+## Code Style
+- ESLint + Prettier enforced via pre-commit hooks
+- Use TypeScript strict mode
+- Follow existing patterns in codebase
+
+## Testing
+Run `yarn test` for vitest. Tests live alongside source files or in `__tests__` directories.
+
+## CLI Commands
+| Command | Description |
+|---------|-------------|
+| `make develop` | Initial setup |
+| `make test` | Run tests |
+| `yarn lint:ts` | TypeScript check |
+| `yarn lint:eslint` | ESLint check |
+| `yarn lint:prettier` | Prettier check |

CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md