Continue Bates numbering across ordered PDFs (#5953)

* feat: add multi-file Bates numbering

* fix(automation): doc_bates_multi rejects a malformed start_number and >> in prefix or suffix, accepts a range ending at u64::MAX, and counts only staged outputs

Addresses CodeRabbit's quick-win notes. Parity is partial until a GUI dialog exists.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

parity/acrobat-features.toml

@@ -2607,11 +2607,11 @@ title = "Bates numbering across multiple files"
 area = "C"
 tier = "P1"
 milestone = "M7"
-status = "planned"
+status = "partial"
 commands = []
-tools = []
-evidence = []
-notes = ""
+tools = ["doc_bates_multi"]
+evidence = ["crates/automation/tests/it/automation.rs::bates_numbers_continue_across_files_and_report_preflight_and_permission_failures"]
+notes = "The headless batch tool allocates inclusive intervals in input order and reports per-file failures; it refuses existing output paths. Missing: a GUI batch dialog (Acrobat sets this up from Header & Footer ▸ Add Bates numbering with a file list), so it is reachable only through `doc_bates_multi`."
 
 [[feature]]
 id = "edit.bates-remove"