chore(infra): default mail driver to sendmail and expose Vue runtime

Mail DEFAULT_DRIVER changes from smtp to sendmail; DRIVER_ORDER is reshuffled so sendmail is the head of the list on fresh installs. This matches what most self-hosted installs already have working out of the box — SMTP requires provider credentials the typical user doesn't have set up yet. The mail config description is rewritten to drop the 'Laravel' framework reference and to explicitly tell unsure users to leave it on sendmail.

SiteApi::get() now catches GuzzleException (the broader interface) and returns null on network failure instead of bubbling the exception object — callers were treating a non-array return as 'marketplace unavailable' anyway, so null is the correct shape.

main.ts exposes the Vue runtime on window.__invoiceshelf_vue so module JS (compiled against the host's Vue install) can call createApp / defineComponent without re-bundling Vue. invoiceshelf.css adds Tailwind source globs for Modules/**/*.{js,ts,vue,blade.php} so module-contributed classes are picked up by the host CSS pipeline.

Installation wizard PreferencesView was already in the tree waiting for the API field rename (date_formats, time_zones, fiscal_years, languages) that landed in setting.service.ts; this commit catches both sides up together.

resources/scripts/api/services/setting.service.ts

@@ -61,7 +61,7 @@ export const settingService = {
     return data
   },
 
-  async getTimezones(): Promise<{ time_zones: string[] }> {
+  async getTimezones(): Promise<{ time_zones: Array<{ key: string; value: string }> }> {
     const { data } = await client.get(API.TIMEZONES)
     return data
   },