Adds two specs for extending issue #294 with bulk uploads:
- bulk-upload-concepts.html — three concepts (stack, split-panel
with file switcher, progressive accordion) with a decision
matrix and the Concept B recommendation.
- bulk-upload-split-panel-spec.html — refined final spec for
Concept B. Covers all three states (N=0 empty · N=1 single ·
N≥2 multi) across 320 / 375 / 768 / 1280 viewports in both
light and dark mode, using the real tokens from layout.css.
Includes impl-ref tables for every new surface, Paraglide keys
in de/en/es, component tree, and backend contract.
The polymorphic-state model means /documents/new is a single
route: N=1 is byte-identical to #294, N=0 shows a whole-panel
drop zone with bulk-first copy, N≥2 grows a file-switcher strip
under the PDF preview plus a two-card form split.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
