feat: Add comprehensive AI coding assistant configuration

  This commit adds configuration for Claude Code and OpenAI Codex CLI to
  improve developer experience when using AI coding assistants with this
  repository.

  ## Claude Code Configuration (.claude/)

  ### Core Files
  - CLAUDE.md: Project guidance with quick start, architecture overview,
    git restrictions, and slash command reference
  - .claudeignore: Excludes build artifacts, dependencies, secrets, and
    other AI agent files from Claude's context

  ### Automation & Safety
  - settings.json: Pre-allowed permissions for common operations,
    denied git write operations (commit/push/add)
  - hooks/pre-tool-use.sh: Blocks dangerous commands, enforces 500-line
    limit for new files, protects auto-generated files
  - hooks/post-tool-use.sh: Auto-formats code with Prettier + ESLint

  ### Productivity Features
  - 6 parallel search agents for fast codebase exploration
  - 7 slash commands (/project:test, /project:build, /project:fix, etc.)
  - 3 detailed guides (architecture, adding-resources, testing)
  - 4 code templates for scaffolding new resources

  ## OpenAI Codex CLI Configuration (.codex/)

  ### Core Files
  - AGENTS.md: Repository context, code patterns, project structure,
    and conventions for Codex to understand the codebase

  ### Skills (.codex/skills/)
  8 reusable task-specific skills:
  - add-resource: Create new API resource with model, class, and tests
  - add-endpoint: Add method to existing resource
  - fix-typescript: Resolve TypeScript compilation errors
  - fix-tests: Fix failing Jest tests
  - fix-lint: Fix ESLint and Prettier issues
  - add-query-params: Add query parameter support
  - handle-binary: Implement binary/stream responses
  - add-pagination: Add pagination support

  ## Build Configuration Updates

  - .eslintignore: Exclude .claude/ from linting
  - .prettierignore: Exclude .claude/ from formatting
  - jest.config.js: Exclude .claude/ from test discovery
  - .gitignore: Ignore /docs (not .claude/docs/), auto-generated
    CLAUDE.md files in subdirectories

  ## Developer Experience

  - Auto-formatting on every edit (Prettier + ESLint)
  - Pre-allowed tools reduce permission prompts
  - Git safety: Claude/Codex write code, developers handle commits
  - New file size limit (500 lines) encourages modular code
  - Templates and guides accelerate onboarding

  ## File Summary

  New files: 35
  - .claude/: 24 files (agents, commands, docs, hooks, shared, settings)
  - .codex/: 8 files (skills)
  - Root: 3 files (CLAUDE.md, AGENTS.md, Makefile, .claudeignore)

  Modified files: 4
  - .eslintignore, .gitignore, .prettierignore, jest.config.js

Author: mqasimca

.claude/agents/codebase-analyzer.md

@@ -0,0 +1,12 @@
+---
+name: codebase-analyzer
+description: Comprehensive analysis using parallel exploration tasks.
+tools: Read, Glob, Grep, Task
+---
+
+Orchestrate parallel analysis:
+1. Spawn explore-resources, explore-models, explore-tests tasks
+2. Aggregate findings
+3. Report: patterns, relationships, gaps
+
+Output: Summary, resources found, patterns identified, recommendations.

.claude/agents/explore-models.md

@@ -0,0 +1,9 @@
+---
+name: explore-models
+description: Search src/models/ for TypeScript type definitions.
+tools: Read, Glob, Grep
+---
+
+Search `src/models/` for interfaces and types.
+Look for: `export interface`, `export type`, `extends ListQueryParams`
+Return: interface names, file paths, key properties.

.claude/agents/explore-resources.md

@@ -0,0 +1,9 @@
+---
+name: explore-resources
+description: Search src/resources/ for API resource classes and methods.
+tools: Read, Glob, Grep
+---
+
+Search `src/resources/` for resource classes extending `Resource`.
+Look for: `public methodName(`, `/v3/grants/`, `interface.*Params`
+Return: file paths, line numbers, method signatures.

.claude/agents/explore-tests.md

@@ -0,0 +1,9 @@
+---
+name: explore-tests
+description: Search tests/ for Jest test patterns and mocks.
+tools: Read, Glob, Grep
+---
+
+Search `tests/` for test files (*.spec.ts).
+Look for: `describe('`, `it('should`, `mockResolvedValue`
+Return: test file, describe blocks, test case names.

.claude/agents/parallel-explore.md

@@ -0,0 +1,13 @@
+---
+name: parallel-explore
+description: Parallel codebase search. Use for broad searches across multiple directories.
+tools: Read, Glob, Grep, Task
+---
+
+Spawn 3-5 parallel Task agents to search different areas:
+- Task 1: `src/resources/`
+- Task 2: `src/models/`
+- Task 3: `tests/`
+- Task 4: Root configs
+
+Use `subagent_type: Explore`. Aggregate results into unified summary.

.claude/agents/quick-search.md

@@ -0,0 +1,9 @@
+---
+name: quick-search
+description: Fast keyword search across codebase using grep.
+tools: Grep, Glob
+---
+
+Use Grep for content, Glob for file patterns.
+Return results as: `file/path.ts:123 - line preview`
+Keep responses concise.

.claude/commands/add-endpoint.md

@@ -0,0 +1,8 @@
+# Add Endpoint: $ARGUMENTS
+
+Format: `{resource} {method}` (e.g., "calendars getAvailability")
+
+1. Add request/response types to `src/models/{resource}.ts`
+2. Add method to `src/resources/{resource}.ts`
+3. Add tests to `tests/resources/{resource}.spec.ts`
+4. Run `make test-resource NAME={resource}`

.claude/commands/add-resource.md

@@ -0,0 +1,9 @@
+# Add Resource: $ARGUMENTS
+
+1. Create `src/models/{name}.ts` with interfaces
+2. Create `src/resources/{name}.ts` extending Resource
+3. Register in `src/nylas.ts`
+4. Create `tests/resources/{name}.spec.ts`
+5. Run `make ci`
+
+Use templates in `.claude/shared/` as reference.

.claude/commands/build.md

@@ -0,0 +1,7 @@
+# Build SDK
+
+```bash
+make build
+```
+
+Output: `lib/esm/`, `lib/cjs/`, `lib/types/`

.claude/commands/explore.md

@@ -0,0 +1,10 @@
+# Parallel Explore
+
+Search for: $ARGUMENTS
+
+Spawn parallel Task agents (subagent_type: Explore) to search:
+- src/resources/
+- src/models/
+- tests/
+
+Aggregate and summarize results.