[Website] i18n module, page-local sections, translatable copy (#21082)

**i18n** — collapsed the ~22 scattered i18n files into a single module
and turned on Spanish alongside French.

**Sections** — dropped the old compound pattern (`Section.Root`,
`Section.Heading`, …). Reusable layout shells moved to `src/templates/`,
atomic bits stay in `design-system/`, and each page now owns its copy in
local `_components` blocks instead of pulling it out of shared sections.
Data files hold arrays only, no prose.

**Copy → `<Trans>`** — A lot of headings were split across several
`<HeadingPart>`s just for font styling, which meant each piece was a
separate translation string. A translator got "Build your Enterprise
CRM" and "at AI Speed" as two unrelated strings and had no way to
reorder them for their language. Those are now single `<Trans>` units
with placeholders. Same idea for the old `\n` + `white-space: pre-line`
line-break trick: replaced with a small `ResponsiveLineBreak` element so
the break is doesn't quietly rot, and did a dead-code pass.

The de-fragmentation changes the message IDs, so around 60 strings will
fall back to English in fr/es until Crowdin re-syncs.

packages/twenty-website/src/sections/ReleaseNotes/components/index.ts

@@ -1,10 +0,0 @@
-import { Divider } from './Divider';
-import { EmptyMessage, Root } from './Root';
-import { ReleaseEntry } from './ReleaseEntry';
-
-export const ReleaseNotes = {
-  Divider,
-  EmptyMessage,
-  ReleaseEntry,
-  Root,
-};

packages/twenty-website/src/sections/ReleaseNotes/index.ts

@@ -1 +1,6 @@
-export { ReleaseNotes } from './components';
+export {
+  Root as ReleaseNotesSection,
+  EmptyMessage as ReleaseNotesEmptyMessage,
+} from './components/Root';
+export { Divider as ReleaseNotesDivider } from './components/Divider';
+export { ReleaseEntry as ReleaseNotesReleaseEntry } from './components/ReleaseEntry';