## Why

Retail and semi-professional investors lack a single tool that turns raw market
data into a clear, defensible thesis on whether an NYSE/Nasdaq-listed company is
over- or undervalued, why, and how to act on it. Existing screeners show numbers
but not judgment; existing chat tools give judgment but aren't wired to live
fundamentals, technicals, and macro context. This change delivers the foundation:
a web app that, given a single ticker, produces a thorough, agent-written
evaluation covering valuation drivers, macro factors, entry/exit points, and
stop-loss levels — with a data layer and agent interface designed to grow.

## What Changes

- Introduce a **Next.js + TypeScript web app** where a user searches a single
  NYSE/Nasdaq ticker and receives a full evaluation report.
- Introduce a **pluggable market-data layer**: a `DataProvider` interface plus a
  default free-tier provider, returning normalized company fundamentals, price
  history, and technical indicators. Paid providers can be swapped in later with
  no changes to consumers.
- Introduce an **equity-evaluation engine** that computes and explains: valuation
  (the specific reasons a company looks over- or undervalued), relevant macro
  factors affecting the stock, candidate entry and exit points, and suggested
  stop-loss levels.
- Introduce a **pluggable analysis-agent layer** backed by **Claude via the
  Anthropic SDK** (bring-your-own API key) that synthesizes the structured data
  into a written investment thesis and the reasoning behind each recommendation.
- Scope v1 to **single-ticker deep evaluation**. Watchlist monitoring, alerts,
  and multi-ticker dashboards are explicitly deferred to later changes.

## Capabilities

### New Capabilities

- `market-data`: A provider-agnostic data layer. Defines the `DataProvider`
  interface and normalized data models (company profile, fundamentals/financials,
  price history, computed technical indicators), plus a default free-tier
  implementation and configuration for selecting a provider.
- `equity-evaluation`: The core analysis engine. Derives valuation signals and
  the reasons behind over/undervaluation, identifies macro factors affecting the
  stock, and computes candidate entry/exit points and stop-loss levels from price
  and volatility data. Produces a structured evaluation object consumed by the
  agent and UI.
- `analysis-agent`: A provider-agnostic agent interface with a default Claude
  (Anthropic SDK) implementation. Takes the structured evaluation as context and
  produces a written thesis: the over/undervalued argument, macro narrative, and
  entry/exit/stop-loss rationale. Handles API-key configuration and graceful
  degradation when no key is present.
- `evaluation-app`: The Next.js web application shell and UI. Ticker search,
  request orchestration (data → evaluation → agent), and the report view that
  presents fundamentals, valuation reasoning, macro factors, a price chart with
  marked entry/exit/stop-loss levels, and the agent's written thesis.

### Modified Capabilities

<!-- None — this is a greenfield project; no existing specs to modify. -->

## Impact

- **New project scaffold**: Next.js + TypeScript app, Tailwind for UI, a charting
  library (e.g. Recharts) for price/technical visualization.
- **New dependencies**: `@anthropic-ai/sdk` for the analysis agent; an HTTP client
  and one free-tier market-data provider SDK/endpoint for the default provider.
- **Configuration/secrets**: environment variables for the market-data API key(s)
  and the Anthropic API key; both treated as bring-your-own and never committed.
- **External services**: one market-data API (rate-limited free tier by default)
  and the Anthropic API. Both isolated behind interfaces so cost/provider choices
  can change without touching evaluation or UI code.
- **Not affected / deferred**: persistence, user accounts, watchlists, real-time
  streaming, alerting, and backtesting are out of scope for this change.