#807: Browse for Themes brings a template's slide master and layouts

Design › Browse for Themes… with a .pptx or .potx now does what PowerPoint
does: the file's first slide master and its layouts replace the master the
current slide uses (a preserved master stays beside it), stretched to this
deck's slide size. Each slide on the old master moves to the new layout with
the same name, else the same kind, and keeps its content as Layout does. One
undo step. A .thmx still brings its theme only.

Reuse Slides' master copy (media, fresh master, layout and shape ids) moves
into reuse::import_master so both commands share it.

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



# Please enter the commit message for your changes. Lines starting
# with '#' will be kept; you may remove them yourself if you want to.
# An empty message aborts the commit.
#
# interactive rebase in progress; onto 22db926
# Last command done (1 command done):
#    pick 8992623 #807: Browse for Themes brings a template's slide master and layouts
# No commands remaining.
# You are currently rebasing.
#
# Changes to be committed:
#	modified:   ROADMAP.md
#	modified:   crates/engine/src/cmd/design.rs
#	modified:   crates/engine/src/cmd/reuse.rs
#	modified:   docs/file-format-parity.md
#

ROADMAP.md

@@ -142,6 +142,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 | 2026-10-15 | A `.pptx` slide that can't be read is reported, not dropped in silence: `lostSlides` from `file.open`, a message and a repaired copy in the app, a warning from `deckcraft-cli` (#203) |
 | 2026-10-16 | AutoFormat as you type: ordinals (1st, 22nd, 103rd) get superscript suffixes after a space or punctuation; Tools ▸ AutoCorrect and `text.autocorrect {ordinals}` turn it off |
 | 2026-10-16 | A PowerPoint Show (`.ppsx`) opened from the command line or the file association starts its slide show, as in PowerPoint; File › Open still opens it for editing (#862) |
+| 2026-10-15 | Design › Browse for Themes… with a `.pptx` or `.potx` brings its slide master and layouts, not just the theme: the master the current slide uses is replaced (a preserved one stays beside it), the template stretches to the deck's slide size, and each slide moves to the layout with the same name or kind and keeps its content. One undo step (#807) |
 | 2026-10-15 | PDF export and rendering: `anchorCtr` centres the drawn text block — right-aligned text no longer ran past the box edge (#736) |
 | 2026-10-14 | connected MCP rejects unrelated, malformed, incomplete and oversized replies without replay; buffered unsolicited bytes force a fresh connection before sending (#718) |
 | 2026-10-14 | Empty bulleted and numbered paragraphs show gray markers while editing, including on first click and after Enter. Markers use the list style and stay out of slide shows and exports. |
@@ -240,6 +241,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 | 2026-10-15 | trivial | Progress log: PPTX trigger click-step round trip. Feature scores and milestone names unchanged |
 | 2026-10-16 | trivial | Progress log: PNG export with a transparent background (#784) |
 | 2026-10-16 | trivial | Progress log: a `.ppsx` from the system starts the slide show (#862) |
+| 2026-10-15 | trivial | Progress log: Browse for Themes applies a template's master and layouts (#807) |
 | 2026-10-14 | trivial | remote MCP checks reply IDs, envelopes and bounded newline framing (#718) |
 | 2026-10-14 | minor | Gray list markers on empty paragraphs while editing; caret keeps the list indent before typing |
 | 2026-10-14 | minor | Community PR wave folded: headline breadth 84% over 191 features (P0 92%, P1 82%, P2 55%) and the feature-area breadths from `cargo xtask parity`; one row per area; Upcoming item 2 merged; per-PR count notes dropped from the progress log. Ready stays ~55%, stage alpha |