The terminal lists the forge's limits with value, default and bounds, and a forge admin changes one after a plan, as MCP `limits` does #7268

For: the owner who hits a limit while working in the terminal and wants to raise it without a browser. Steering means the dials are where they are.

listLimits and changeLimit are reached from /admin/limits and MCP limits (src/http/mcp/tools/limits.ts). No terminal screen calls them.

Done:

• [ ] A new src/tui/screens/limits.ts, opened from the palette in src/tui/forge.ts as "Limits" for a forge admin who is a person. Each row: key, value, default and bounds.
• [ ] e on a row asks for a value, shows the plan (from → to) and changes it only after a confirm; an empty value restores the default; out-of-bounds is refused in the same words as MCP.
• [ ] An agent or a non-admin is never offered the screen.
• [ ] A new test/tui-limits.test.ts: list, change one after a confirm, restore the default, refuse out of bounds; esc changes nothing.

Files: src/tui/screens/limits.ts, src/tui/forge.ts, one test. Risk: low; reuse the functions, add no rule.