Add stories for side panel composers (#24700)

## Summary

- add a full side-panel calendar event composer story following #24667
- add a matching full side-panel email composer story
- share realistic connected-account, calendar-channel, recipient, and
side-panel setup between both stories
- exercise useful ready-to-submit states in Chromium instead of only
mounting the components

This is a follow-up to #24667. Because that PR is merged, this PR is
based directly on `main`.

## Validation

- `yarn nx build twenty-shared --skip-nx-cache` ✅
- `STORYBOOK_SCOPE=modules npx vitest run
src/modules/side-panel/pages/__stories__/SidePanelComposerPages.stories.tsx`
✅ (2 Chromium stories)
- `yarn nx run twenty-front:lint:diff-with-main --skip-nx-cache` ✅
- `git diff --check` ✅
- `../../node_modules/.bin/tsgo --noEmit -p tsconfig.json` ⚠️ remains
blocked by pre-existing unrelated `SidePanelPages` enum errors in
`src/modules/front-components/hooks/__tests__/useFrontComponentExecutionContext.test.tsx`;
the new story reports no type error.

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