TSA-277: [FE] style Document page

[illiaboiko]

closes #277

updated 2026-09-21

updated design after discussion with Product Owner in slack thread here

Restructured the document page into its own directory (pages/document/) with a component per section (DocumentTitleBlock, PagesBlock, TranscriptionBlock, VerificationBlock, ExportBlock, GroundTruthBlock) sharing a common DocumentSection wrapper, instead of one large file.

Implemented

• Pages block (new) — a 7-segment progress bar (verified / skipped / blank / failed / ready-to-check / in-work / pending). Shows both cursors: "you: page N" (verification cursor) and "model: page N".
• Transcription block — narrowed to model-only stats: pages read by the model (bar + count), budget spent/limit (existing BudgetIndicator, unchanged), and blank/failed page counts as plain informational text (no actions). Excludes cost-per-page and a reviewing-pace ETA — both need backend view wiring not yet done.
• Verification block — copy narrowed to: "X of Y reviewed" (reviewed = verified + skipped, i.e. pages the human seen and make an action on, not just confirmed/corrected ones), a resume link/keyboard shortcut (unchanged from v1).
• ** Export block** - just a placeholder/mock - without functionality

What to test

• Verify Pages block renders correctly across a document with pages in every status bucket
• Verify budget-stop banner + raise-limit dialog
• Verify failed-document state renders DocumentFailedBlock and retry works
• Check light/dark theme

[illiaboiko]

For the record, I discussed with Product Owner the redesign of the Document page to match the general app idea. Also, after we reviewed and closed PRs #302 and #293, there will be significant refactoring. I'll close this PR, update the ticket #277 's description and open a new PR.