Build stock-deep-evaluation v1: single-stock equity evaluation app

Next.js 15 + TypeScript app implementing the fully-specced first change.
Pipeline: resolve -> market data -> pure evaluation engine -> budget guard
-> analysis agent -> report.

- market-data: DataProvider interface, offline FixtureProvider (DE/SPY seeded
  from the reference example), FmpProvider (FMP free tier), TTL cache + retry.
- technicals: pure MA/volatility/swing/52-week math.
- evaluation: instrument-aware pure engine; equity branch built, ETF gated to
  "not yet supported". Reproduces the DE example (P/E 34.5, fwd 29.3, $167.6B).
- agent: AnalysisAgent interface; default Claude Code CLI transport (headless,
  subscription-backed, web-grounded), Anthropic API alternate via config.
- cost-controls: price table, spend store, monthly budget guard.
- UI: ticker search + deep-dive toggle, report view, price chart with marked
  entry/exit/stop levels, cost/budget display, ETF/not-found states.

31 vitest tests, typecheck, production build, and lint all pass. Verified
end-to-end via the API for DE, SPY, and an unknown ticker. Live Claude CLI
agent test is the documented pick-up point (see README).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.env.example

@@ -0,0 +1,26 @@
+# Copy to .env.local and fill in. .env.local is gitignored and never sent to the browser.
+
+# --- Analysis agent transport ---
+# "claude-cli" (default): runs the local Claude Code CLI in headless mode on your
+#   existing Claude auth (e.g. subscription). No API key needed; near-zero marginal
+#   cost for internal use. Requires `claude` to be installed and authenticated.
+# "api": uses the Anthropic API via @anthropic-ai/sdk (metered). Use this if the
+#   app will serve external users.
+AGENT_TRANSPORT=claude-cli
+
+# Anthropic API key — only used when AGENT_TRANSPORT=api. Server-side only.
+ANTHROPIC_API_KEY=
+
+# --- Market data ---
+# Which market-data provider to use: "fixture" (offline demo data) or "fmp".
+# Defaults to "fixture" when unset so the app runs with zero configuration.
+MARKET_DATA_PROVIDER=fixture
+
+# Market-data provider API key (default provider: Financial Modeling Prep free tier).
+# Get a free key at https://site.financialmodelingprep.com/developer/docs
+MARKET_DATA_API_KEY=
+
+# --- Cost controls ---
+# Optional monthly spend budget in USD for the cost guard. 0 or unset = disabled.
+# (With the claude-cli transport on a subscription, reported marginal cost is ~$0.)
+MONTHLY_BUDGET_USD=0