Move shared components to a packages/ directory (#30962)

* Move shared components to a packages/ directory

so they can be publish more sensibly

* Iterate towards split out shared-components module

 * Move shared component source into src/ subdir
 * Fix up imports
 * Include shared components in babel-ing (again)

* Remove now unused dependencies

* Update import in storybook preview

* ...except of course they aren't unused

if we import the shared components by source

* Ignore shared components deps

* Add shared-components to i18n paths

and upgrade web-i18n to version that supports doing so

* Move storybook stuff to shared-components

* Seems we don't need this anymore...

* Remove unused deps

and remove storybook plugin from eslint

* Presumably working-directory is only valid on run steps

* Ignore dep & run prettier

* Prettier on knips.ts

* Hopefully run in right dir

* Remember how to software write

* Okay... how about THIS way?

* Oh right, they were git ignored. Sigh.

* Add concurrently

* Ignore in knip

* Better?

* Paaaaaaaackageeeeeeees

* More packages

* Move playwright snapshots

* Still need a custom snapshots dir

* Add eslint back

* Oh, now knip sees them

* Fix another import

* Don't lint shared-components with everything else

Okay, eslint & tsconfig are tied too closely for this to work and
running tsc on the shared components will need its deps installing

* Maybe lint shared components

please?

* Not quite

* Remove storybook again

Re-check if it does work without it

* Remove storybook eslint plugin

as we're not linting storybook here anymore

* Remove this too

* We do need it here though

.github/workflows/static_analysis.yaml

@@ -35,6 +35,12 @@ jobs:
             - name: Typecheck
               run: "yarn run lint:types"
 
+            - name: Install Shared Component Dependencies
+              run: "yarn --cwd packages/shared-components install"
+
+            - name: Typecheck Shared Components
+              run: "yarn --cwd packages/shared-components run lint:types"
+
     i18n_lint:
         name: "i18n Check"
         uses: matrix-org/matrix-web-i18n/.github/workflows/i18n_check.yml@main
@@ -81,6 +87,12 @@ jobs:
             - name: Run Linter
               run: "yarn run lint:js"
 
+            - name: Install Shared Component Deps
+              run: "yarn --cwd packages/shared-components install --frozen-lockfile"
+
+            - name: Run Linter
+              run: "yarn --cwd packages/shared-components run lint:js"
+
     style_lint:
         name: "Style Lint"
         runs-on: ubuntu-24.04