tri-bot: Replace claude CLI with direct Anthropic API (SSE streaming)

[gHashTag]

Problem

tri-bot streams via claude -p --output-format stream-json — spawns Node.js/TypeScript Claude CLI as subprocess. This is the last TypeScript dependency in the Telegram→Claude pipeline.

Solution

Rewrite claude_stream.zig to POST directly to api.anthropic.com/v1/messages with "stream": true, parse SSE events inline.

Changes

• claude_stream.zig — FULL REWRITE: std.http.Client + SSE parser replaces std.process.Child
• telegram_api.zig — add api_key to BotConfig
• handlers.zig — /status uses git commands directly (no claude), /sessions stubbed
• bot_loop.zig — /continue, /resume deferred to Phase 5 (sessions)
• main.zig (bot) — read ANTHROPIC_API_KEY from env

Architecture after

Telegram → tri-bot (Zig) → api.anthropic.com (HTTPS/SSE)

Zero Node.js. Zero subprocess. Pure Zig HTTP.

Acceptance Criteria

• tri-bot compiles and runs
• /ask streams text via SSE from Anthropic API directly
• /stop cancels HTTP connection (no SIGTERM)
• /status shows git info without claude CLI
• No std.process.Child calls to claude binary remain