Making a forge says what each follow mode does: tell-me opens an inbox card, take-updates opens a pull — not "recorded for now" #7199

For: the person making a forge is told the truth about how it follows this forge's code.

Today /forges/new (src/web/pages/new-forge.ts:223-243) says "recorded for now; nothing acts on it yet", and the terminal's new-forge screen (src/tui/screens/newforge.ts:42 and :124) says "Recorded for now: nothing tells you or takes updates yet." Both are out of date: src/spawn/upstream.ts:161-171 acts on both modes. tell-me sends the owner an inbox card when the parent's code moves (#2633). take-updates opens one pull from forge/take-updates (src/spawn/take.ts). MCP spawn's followMode (src/http/mcp/tools/spawn.ts:30) has no description at all.

Done:

• [ ] On /forges/new, each radio says in one plain line what happens: tell-me tells the owner in their inbox when this forge's code moves. take-updates opens a pull with the new code, and a person merges it. The legend no longer says "recorded for now".
• [ ] The terminal's new-forge hint and its review line say the same words. They come from one module that both read, for example src/spawn/follow_words.ts or an existing words module.
• [ ] MCP spawn's followMode has a description in the same words, and docs/MCP.md matches if it lists the field.
• [ ] test/new-forge.test.ts and test/tui-newforge.test.ts assert the new words and that "Recorded for now" appears nowhere. Change those tests only where they pinned the old wording.
• [ ] bun scripts/design-lint.ts passes.

Files: src/web/pages/new-forge.ts, src/tui/screens/newforge.ts, src/http/mcp/tools/spawn.ts, the two tests. Risk: low. Words only, no behaviour change.