Document PDF watch mode in Fullbleed 2.5 - #4

Problem and change

Document the 2.5.0 CLI watcher with a complete invoice command, explicit dependency rules, save/error recovery, JSON result streaming, and delivery-gate limits. Add navigation and homepage links, and update the CLI reference's watch flags and release provenance.

Keep this draft until fullbleed-engine/fullbleed-official#10 is released and the public 2.5.0 wheel is verified. Versioned source and release links intentionally target that release.

Validation

• Strict MkDocs build passed.
• All 40 generated HTML pages passed internal-path, anchor, and search-metadata checks.
• Browser checks at 390 and 1440 pixels found no horizontal page overflow; the copy button produced the complete expected example commands.
• Feature behavior is covered by installed-process Windows/Linux CI in core PR Add a Rust quickstart with verified document examples #9 and the release candidate's installed 2.5.0 smoke run. Public-package verification and live external-link checks remain publication gates.