Add comprehensive zh-Hans localization coverage across menu, settings, and notifications

[ShawnRn]

What this PR does

This PR adds and wires comprehensive Simplified Chinese (zh-Hans) localization coverage across CodexBar UI surfaces, with a focus on menu bar content and provider-related views.

Summary of changes

• Added localization infrastructure:

• Introduced a shared localization helper (L10n) for consistent string lookup/formatting.

• Added en.lproj/Localizable.strings and zh-Hans.lproj/Localizable.strings.

• Set package default localization to English.

• Localized previously hardcoded UI text in:

• Menu card sections (usage, reset, credits, cost, history, status details).

• Preferences panes and provider detail/settings rows.

• Provider actions/submenus and status-related text.

• Session quota notifications and related wording.

• Relative/updated/reset time labels and format strings.

• Fixed several missed/edge strings reported during manual QA:

• Notification body/title phrasing and punctuation.

• “Updated just now” and related freshness strings.

• Percentage word order for zh-Hans (e.g. 剩余 32%).

• “Session depleted” phrasing changed to quota-oriented Chinese wording.

• Cost history empty-state and hover/detail labels.

Behavior notes

• English layout/wording is preserved.
• zh-Hans wording is adjusted for natural Chinese reading order.
• Dynamic strings now use format keys where needed so zh-Hans and English can differ safely.

Validation

• Ran ./Scripts/compile_and_run.sh after each edit cycle.
• Build/package/relaunch succeeded.
• App launches and runs with updated localized resources.

Scope / non-goals

• This PR is focused on UI localization coverage and string wiring.
• No provider fetching logic changes were introduced.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 7214ede5eb

ℹ️ About Codex in GitHub

Codex has been enabled to automatically review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".

[chatgpt-codex-connector]

Remove duplicated suffix from zh-Hans pace ETA

In detailRightLabel, etaText comes from durationText, which only strips the English in prefix; after this commit localizes countdown strings (e.g. zh-Hans in %dh -> %d 小时后), etaText already contains the trailing 后. Formatting that value with Runs out in %@ (zh-Hans: %@ 后耗尽) yields duplicated wording like 3 小时后 后耗尽, so zh-Hans users see broken pace text whenever an ETA is shown.

Useful? React with 👍 / 👎.