Groundwork for #1219. The menubar app hardcoded ~530 English strings across
Views/, the presentation structs, the status-item menu and the update alerts,
so there was nothing for a translator to translate.
Every user-facing literal now goes through `L(_:)` / `L(_:_:)`, which look the
string up in `Localizable.strings` in the SwiftPM target resource bundle. The
key *is* the English copy, so English stays the development language and a
missing translation degrades to correct English instead of a dotted
identifier. `en.lproj` is therefore an identity table; it exists so the bundle
advertises `en` and so a translation can be diffed against it.
Why the lookups are explicit rather than relying on SwiftUI's implicit
`LocalizedStringKey`: SwiftPM emits target resources into a sibling bundle
(`CodeBurnMenubar_CodeBurnMenubar.bundle`) that the packaging scripts copy into
`Contents/Resources`. `Bundle.main` has no `.lproj` at all, so `Text("literal")`
would always miss. Naming `Bundle.module` is the one form that resolves the
same way in `swift run`, in `swift test` and in the packaged `.app`.
Enum raw values that double as identity (`Period`, `MenubarScope`,
`InsightMode`, `AccentPreset`, `ProviderFilter`) keep their raw value and gain
a `displayLabel`, so persistence and cache keys are untouched by translation.
Three display-only date formatters that were pinned to `en_US_POSIX` with fixed
patterns now use `setLocalizedDateFormatFromTemplate`, and the calendar
popover's weekday row comes from the locale's own symbols. The `yyyy-MM-dd`
formatter stays POSIX: it parses and builds data keys, not display text.
Not extracted, deliberately: provider, model and plan names; units; currency
codes; shell commands and paths; quota window labels that policy code matches
on by English substring (`QuotaSummary.headlineWindow`); and anything the
`codeburn` CLI produces.
Also copies the SwiftPM resource bundle into the app in build-local.sh, using
the named-bundle + `[[ -d ]]` pattern package-app.sh already uses. Without it
the assembled app finds no strings table (and already trapped on first icon
load, the resource-bundle half of #1262).
