The homepage demo card has only shown Sheets and Docs since v0.3.
Slides is now the third shipped module, so the demo needs a live
preview tab to back up the new 3-product Hero copy.

Mirrors the Docs lazy-mount + theme-postMessage pattern: the Slides
iframe mounts on first tab activation and stays mounted across
switches; theme changes propagate without reload. Default active
tab stays Sheets so the most-polished demo loads first.

Token default is the brainstormed demo presentation; override via
VITE_DEMO_SLIDES_SHARED_TOKEN.

Hero H1 and Footer brand copy said "Word Processor & Spreadsheet"
— accurate when only Sheets and Docs shipped, but misleading now
that Slides is the third released module. Replace the product
enumeration with a single suite phrase ("The Office Suite") and
move the module list into the sub copy / footer paragraph.

H1 max-width relaxes from 16ch to 20ch since the new title is
shorter and lets the italic emphasis sit on its own line at most
breakpoints.

The secondary feature grid had 4 cards — 2 Sheets-specific, 1
Docs-specific, 1 cross-cutting (Sharing & Permissions) — and 0
for Slides. With Slides now a first-class module, the imbalance
made the lineup feel Sheets-heavy and silently omitted the new
product.

Replace with 6 cards in a product-balanced 2/2/2 layout (Sheets:
Formulas + Charts; Docs: Page-Based Editor + Tables & Pagination;
Slides: Themes & Layouts + Presentation Mode). The grid markup
stays md:grid-cols-2, so 6 cards render as 3 rows of 2 without
layout changes.

"Sharing & Permissions" overlapped the Real-Time Collaboration
hero card directly above, so dropping it removes a duplicate
without losing coverage.

UseCasesSection card 2 was a near-duplicate of card 1 (both
Sheets-only customer-data scenarios), so the page told the
"Slides shipped" story in Hero and Demo but went silent on
real-world Slides use in the use-cases section. Replace card 2
with a pitch-deck case that highlights themes/layouts/self-host
— deliberately staying away from live Sheets-cell embedding,
which isn't implemented yet.

WhySection's "Sheets & Docs in one app" comparison row reads as
"missing Slides" once Slides is part of the suite story; relabel
to "Slides, Docs & Sheets in one app". Google Workspace still
gets a checkmark in that column — they also ship all three.

The docs site has shipped guides for Sheets and Docs since v0.3 but
silently omitted Slides — every "What's Next" link in homepage cards
pointing at /docs/slides/* used to 404. Add the missing surface so
the homepage's Slides links resolve and new users have a first-day
reference.

Three pages mirror the existing Sheets/Docs structure:

- Build a Deck — end-to-end tutorial, counterpart to Build a Budget
- Themes & Layouts — theme + 11 layouts + placeholders reference
- Keyboard Shortcuts — catalog grouped by category

Nav and sidebar position the Slides group between Docs and
Developers so the order reads as a coherent product progression
(Guide, Sheets, Docs, Slides, Developers).

Shapes / connectors / presentation-mode deep dives are intentionally
deferred — they'll land in follow-up PRs as the surface area
stabilizes.

The homepage and docs-site design docs went stale after the 3-product
suite refresh — they still described "Word Processor & Spreadsheet"
copy, two demo tabs, four secondary cards, and a sheets-and-docs-only
documentation tree.

Bring both docs back in sync with the shipped code so they're
authoritative again: new Hero phrasing, three demo tabs with the
Slides token / lazy-mount story, the 3×2 product-balanced features
grid, the Slides pitch-deck UseCase, the updated WhySection row, and
the Slides documentation group in the VitePress nav and sidebar.

The hero eyebrow read "v0.3" and the demo footer read
"[email protected]" — both hardcoded strings that drifted apart from
the actual package version (now 0.4.1) and would silently rot at
every release. The Slides reframe forced an audit, so fix the
root cause: read the root package.json version at vite config time
and inject it as a build-time constant.

`__APP_VERSION__` is declared in vite-env.d.ts so TypeScript sees
it. The hero displays the marketing-style minor tag ("v0.4") by
slicing off the patch; the demo footer keeps the full
developer-style stamp ("[email protected]"). Bumping the root
package.json is now the single touch point at release time.

Browser-driven wrapping at large viewports kept "The Office Suite
You Can Own" on a single line at most desktop widths, which buried
the italic emphasis. The intended display is two stacked phrases
where the syrup-deep italic "You Can Own" lands directly below the
white "The Office Suite" — that's how the design reads as a
declarative statement instead of a long compound noun.

Switch to `block` spans on each half. The em keeps its italic +
syrup-deep styling. `max-w-[20ch]` drops since the forced line
break makes it redundant.

Three findings from the self code-review pass.

The Slides demo footer tip said "press F to present" — but Slides
has no F-key handler, only ⌘/Ctrl+Enter (current) and
⌘/Ctrl+Shift+Enter (first), as documented in this same PR's
keyboard-shortcuts page. F would only trigger browser fullscreen,
not the Slides player. Update the tip to match the real shortcut.

The WhySection comparison row read "Slides, Docs & Sheets in one
app" while every other place on the page used "Sheets, Docs, and
Slides". Align the row to the same ordering for consistency.

The "Tables & Pagination" feature card linked to writing-a-document
— the same href as the "Page-Based Document Editor" card — and the
target page covered neither tables nor pagination. Add Tables and
Pagination sections to writing-a-document.md and anchor the Tables
card to #tables so each card lands on relevant content.