Added draft state handling

[tammi-23]

implement #1480

[Copilot]

Pull request overview

Implements draft state handling for the mail compose flow, including save/discard behaviors and draft mailbox discovery.

Changes:

• Added a draft API connector + composable to create/replace/delete drafts and to manage dirty/saving state.
• Refactored Pinia stores to sync selected IDs with route query parameters via a shared helper.
• Updated UI to prompt on close, auto-save drafts periodically, and show a “Saved” hint.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
packages/web-app-mail/src/helpers/mailDraftConnector.ts	Adds an HTTP-backed connector implementing the draft API.
packages/web-app-mail/src/composables/useSaveAsDraft.ts	Introduces draft-saving/discarding composable with dirty/saving state.
packages/web-app-mail/src/composables/piniaStores/mails.ts	Refactors selected mail handling to use route query binding helper.
packages/web-app-mail/src/composables/piniaStores/mailboxes.ts	Refactors mailboxes store and adds computed drafts mailbox selection.
packages/web-app-mail/src/composables/piniaStores/accounts.ts	Refactors accounts store and binds current account to route query.
packages/web-app-mail/src/composables/piniaStores/helpers.ts	Adds helper to normalize route query values into a single string.
packages/web-app-mail/src/components/MailboxTree.vue	Fixes mailbox selection flow to avoid deref’ing missing account.
packages/web-app-mail/src/components/MailWidget.vue	Adds leave-confirm modal, auto-save, and draft integration to compose modal.
packages/web-app-mail/src/components/MailList.vue	Mounts compose widget only when open; fixes seen-flag update source.
packages/web-app-mail/src/components/MailListItem.vue	Sanitizes HTML-like preview content before rendering preview text.
packages/web-app-mail/src/components/MailComposeForm.vue	Stabilizes props defaults + fixes modelValue usage after toRefs().

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[Copilot]

Pull request overview

Copilot reviewed 15 out of 15 changed files in this pull request and generated 6 comments.

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