#708 Eager render stack (Ink/yoga-layout + marked-terminal) adds ~540ms to every command's startup

Summary

The terminal-render stack — Ink/React (+ the yoga-layout WASM engine) and marked-terminal (+ highlight.js) — is statically imported through the command tree, so it loads on every invocation, including commands that render no TUI and no markdown (--version, config list, model list, anything with --json, all non-interactive *search). It costs ~540 ms (~27%) of startup that the vast majority of commands never use.

Impact

Every non-rendering subcommand pays ~540 ms of import/instantiate cost for code it doesn't execute. Since the per-command telemetry tax is now small, this eager render stack is the single largest reducible component of the startup floor — and it's paid on essentially every invocation.

Evidence

1. Startup CPU attribution (deno run --v8-flags=--prof main.ts --version, node --prof-process, ~551 in-V8 ticks):

~80% of in-V8 startup CPU is the render stack.

2. Module-stub POC — aliasing the four entry packages (ink, react, marked, marked-terminal) to no-op stubs in deno.json (dropping their transitive closure from the loaded graph):

--version still printed correctly and exited 0 under the stubs, so this is the genuine cost of loading a stack --version never uses, not a crash-fast artifact. Stubbed runs were also far more stable (no multi-second tail).

Root cause

• src/presentation/markdown_renderer.ts statically imports marked + marked-terminal (and instantiates them at module eval), and is pulled in by ~8 renderers.
• The Ink .tsx renderers statically import ink/react; ink instantiates the yoga-layout WASM engine at import time (~228 ms) regardless of whether any TUI is shown.
• All of these are reachable statically from the command tree built in src/cli/mod.ts, so they load for every command.

Proposed fix

Lazy-load the render stack so only commands that actually render pay for it (once, on first render):

• Split each Ink .tsx renderer from its command definition; await import("./<renderer>.tsx") inside the .action() handler, gated on interactive-TTY mode (not --json, isatty). Keeps the Cliffy command tree light.
• Make markdown_renderer.ts's render functions async and dynamic-import() marked/marked-terminal on first use.

Estimated recovery: ~540 ms (~27%) off startup for the ~80% of invocations that render neither a TUI nor markdown.

Environment

• swamp current main (and shipped 20260619); the eager static imports are present in main
• macOS, Intel x86_64
• Measured from source via deno run (warm cache); the shipped binary embeds a snapshot but reaches the same ~1.9 s floor