fix(agy): render structured print-mode progress

[timmikk]

Agy print mode emits stream-json NDJSON, but Happy treated stdout as plain text. This change parses the structured stream and renders Agy activity using Happy's existing mobile protocol and native tool cards.

What changed:

• Buffer fragmented agent_response deltas per response step, then emit each complete progress message before the following tool call.
• Use the terminal aggregate only as a fallback, avoiding duplicated progress/final responses.
• Pair tool lifecycle events with stable per-turn call IDs.
• Translate common Agy tools to native Happy cards (Read, LS, Bash, Edit, Write, Grep, Glob, WebFetch, and WebSearch).
• Render manage_task and call_mcp_tool as concise native command cards instead of raw JSON.
• Surface selected command/task/MCP/search results through the existing phone-compatible progress-text path.

Safety:

• Only allowlisted scalar input fields are forwarded; file contents, edit bodies, arbitrary nested arguments, and file/list outputs remain hidden.
• Credential-bearing commands and selected outputs are redacted.
• Tool names, arguments, outputs, record sizes, response buffering, and per-turn tool/response counts are bounded.
• Raw stderr and malformed stream contents are not logged.

Validation:

• pnpm --filter happy test passes (87 files, 829 tests).
• Focused Agy/ACP/CLI-argument suite passes (53 tests).
• Real Agy stream-json probes confirmed response-fragment and tool-output shapes.
• Isolated ahjo-dev phone testing confirmed native file/task/MCP/search cards, visible command results, cancellation, one final response, and complete progress comments arriving before their commands without awkward fragment splits.