feat(cli): persist project-scoped prompt history

[lifelmy]

Summary

Closes #1125.

• persist CLI prompt history per project by default while preserving the existing global history path behind FREEBUFF_HISTORY_SCOPE=global
• cap persisted history at 500 entries by default and collapse consecutive duplicate prompts
• add FREEBUFF_HISTORY_SIZE=0 as an explicit off switch for prompt history persistence
• document the plaintext on-disk history behavior and configuration in the CLI README
• keep recalled entries editable before resubmission through the existing up/down recall flow

Testing

• bun install
• ./node_modules/.bin/prettier --write cli/README.md cli/src/chat.tsx cli/src/hooks/use-input-history.ts cli/src/utils/message-history.ts cli/src/utils/tests/message-history.test.ts
• git diff --check
• bun test cli/src/utils/tests/message-history.test.ts cli/src/hooks/tests/use-input-history.test.ts cli/src/utils/tests/keyboard-actions.test.ts cli/src/utils/tests/chat-input-key-intercept.test.ts — 111 pass, 0 fail, 213 expect() calls
• bun run build:sdk
• bun run build:freebuff

Notes

I also tried the broader CLI checks. cd cli && bun run typecheck currently fails because this checkout is missing existing dependencies/types for tar and react-dom/server; cd cli && bun run test currently fails before running tests because cli/bunfig.toml preloads missing ../test/setup-scm-loader.ts.

I use a coding assistant to help implement, and I review and take responsibility for the final change.