Add project docs and initial configuration

- PRD.md: full product requirements for the budget app
- CLAUDE.md: repo guidance including td task management workflow
- AGENTS.md: session startup instructions
- .gitignore: comprehensive ignore rules for Node/React/Docker/editor artifacts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

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+# td / sidecar
+.todos/
+.sidecar/
+.sidecar-agent
+.sidecar-task
+.sidecar-pr
+.sidecar-start.sh
+.sidecar-base
+.td-root
+
+# Dependencies
+node_modules/
+
+# Build output
+dist/
+build/
+.vite/
+
+# Environment
+.env
+.env.local
+.env.*.local
+
+# Logs
+logs/
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Editor
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# Coverage
+coverage/

AGENTS.md

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+## MANDATORY: Use td for Task Management
+
+Run td usage --new-session at conversation start (or after /clear). This tells you what to work on next.
+
+Sessions are automatic (based on terminal/agent context). Optional:
+- td session "name" to label the current session
+- td session --new to force a new session in the same context
+
+Use td usage -q after first read.

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Task Management
+
+This project uses `td` (a local CLI) for task tracking. At the start of each session:
+
+```bash
+td usage --new-session   # required at conversation start or after /clear
+td usage -q              # quick check for subsequent reads
+```
+
+Optional session labeling:
+```bash
+td session "name"        # label the current session
+td session --new         # force a new session in the same terminal context
+```
+
+Task state is stored in `.todos/issues.db` (SQLite).

PRD.md

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+# Budget App — Product Requirements Document
+
+## Overview
+
+A self-hosted web app for managing semi-monthly paychecks and bill assignments. The user gets paid twice a month and wants to plan which bills come out of each paycheck, track actuals, and see monthly/annual summaries.
+
+## Tech Stack
+
+| Layer | Choice | Reason |
+|---|---|---|
+| Frontend | React (Vite) | Component-based UI, fast dev server |
+| Backend | Node.js + Express | REST API |
+| Database | PostgreSQL | Docker-hosted, safe for concurrent LAN access |
+| Hosting | Docker Compose | Self-hosted on LAN, single `docker compose up` |
+
+## Architecture
+
+```
+Docker Compose
+├── app (Node/Express + serves React build)
+└── db  (PostgreSQL)
+```
+
+The Express server both serves the React frontend (static build) and exposes a `/api` REST layer. In development, Vite dev server proxies API calls to Express.
+
+---
+
+## Configuration
+
+- **Pay dates**: Configurable. Default: 1st and 15th of each month.
+- **Pay amount**: Configurable gross and net per paycheck (can differ between the two).
+- No authentication — single-user app.
+
+---
+
+## Core Concepts
+
+### Paycheck
+A paycheck represents one pay period (e.g. "March 1" or "March 15"). Each paycheck has:
+- Pay date
+- Gross amount
+- Net (take-home) amount
+- List of assigned bills/expenses
+- Remaining balance = net − sum of assigned amounts
+
+### Bill
+A recurring monthly charge assigned to a specific paycheck each month. Fields:
+- Name
+- Amount
+- Due date (day of month)
+- Assigned paycheck (1st or 15th)
+- Category (e.g. Housing, Utilities, Subscriptions, Insurance)
+- Active/inactive flag
+
+Bill frequency is **monthly only** in v1.
+
+### Variable Expense
+A spending category (e.g. Groceries, Gas) with no preset budget. Actuals are logged against a paycheck. No budget target in v1.
+
+### Savings Goal
+A named savings allocation assigned to a paycheck with a fixed monthly contribution amount.
+
+### One-Time Expense
+A non-recurring expense manually assigned to a specific paycheck for a specific month.
+
+### Actual
+A logged transaction recording what was actually spent. Linked to a bill or expense category and a paycheck period.
+
+---
+
+## Views
+
+### 1. Paycheck View (main view)
+Two-column layout per month — one column per paycheck.
+
+Each paycheck column shows:
+- Pay date + label (e.g. "March 1")
+- Gross / Net pay
+- List of assigned bills with amounts and due dates
+- Paid / unpaid toggle per bill
+- Variable expense actuals (logged amounts)
+- Savings goal allocations
+- One-time expenses
+- **Remaining balance** (net − all assigned amounts)
+
+Navigation: month-by-month (prev/next).
+
+### 2. Monthly Summary
+Per-month aggregate view:
+- Total income (both paychecks)
+- Total planned bills
+- Total actuals logged
+- Surplus/deficit
+
+### 3. Annual Overview
+Year-at-a-glance:
+- Monthly totals in a table/grid
+- Annual income, planned spend, actual spend
+- Running surplus/deficit
+
+---
+
+## Data Model (PostgreSQL)
+
+```sql
+-- App configuration
+config (key, value)
+
+-- Bill definitions
+bills (id, name, amount, due_day, assigned_paycheck, category, active, created_at)
+
+-- Paycheck instances per period
+paychecks (id, period_year, period_month, paycheck_number, pay_date, gross, net)
+
+-- Bills assigned to a paycheck period (overrides allowed per period)
+paycheck_bills (id, paycheck_id, bill_id, amount_override, paid, paid_at)
+
+-- Savings goals
+savings_goals (id, name, amount, assigned_paycheck, active)
+
+-- One-time expenses
+one_time_expenses (id, paycheck_id, name, amount, paid, paid_at)
+
+-- Variable expense categories
+expense_categories (id, name)
+
+-- Actual spending log
+actuals (id, paycheck_id, category_id, bill_id, amount, note, date, created_at)
+```
+
+---
+
+## Build Phases
+
+### Phase 1 — Skeleton
+- Docker Compose setup (app + postgres)
+- Express app with health check
+- React app shell (Vite, routing)
+- Database migrations (all tables)
+- Basic config API (get/set pay dates, pay amounts)
+
+### Phase 2 — Bills & Paychecks
+- Bills CRUD (API + UI)
+- Paycheck generation (auto-create paycheck records for a month)
+- Paycheck view (assign bills, show balance)
+
+### Phase 3 — Tracking
+- Mark bills paid/unpaid
+- Log variable expense actuals
+- One-time expenses
+
+### Phase 4 — Summaries
+- Monthly summary view
+- Annual overview