Automatically detect v1 endpoint on base URL input

[GT-610]

Related to #1165.

Summary by CodeRabbit

• Improvements

  • Redesigned AI settings UI with clearer "API Endpoint" labeling and helper instructions explaining endpoint configuration options.
  • Added multilingual support for AI endpoint setup guidance in English, Chinese, and Traditional Chinese.

• Configuration

  • Updated default AI model to gpt-5.4-mini.

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR adds flexible AI endpoint configuration by introducing a URI normalization method that automatically completes Chat Completions endpoint URLs. The new composeChatCompletionsUri() method handles three cases: appending /v1/chat/completions for service root URLs, appending /chat/completions for existing /v1 endpoints, and leaving complete endpoints unchanged. The default AI model is updated to gpt-5.4-mini, localization strings are added to explain the endpoint behavior, and the settings UI is enhanced to display contextual help text. Tool-call description extraction is refined to prefer explicit description fields, and exception handling is reformatted for clarity.

Possibly related PRs

• lollipopkit/flutter_server_box#936: Modifies AskAiRepository endpoint URI composition and handling in the same file.
• lollipopkit/flutter_server_box#940: Changes _buildRequestBody localeHint fallback behavior in AskAiRepository.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: implementing automatic detection and handling of the v1 endpoint when users provide a base URL, which is the core functionality added via the composeChatCompletionsUri helper across all modified files.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-ask-ai-endpoint-normalization

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[coderabbitai]

🧹 Nitpick comments (1)

test/ask_ai_repository_test.dart (1)

4-36: 💤 Low value

LGTM!

Good test coverage for the three main endpoint scenarios. The tests verify the core functionality of composeChatCompletionsUri.

Consider adding edge case tests for trailing slashes (e.g., https://api.openai.com/v1/) and URLs with ports to increase confidence in the implementation.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@test/ask_ai_repository_test.dart` around lines 4 - 36, Add tests covering
edge cases for trailing slashes and URLs with ports to ensure
AskAiRepository.composeChatCompletionsUri handles them correctly; specifically,
add one test that passes a base URL ending with a trailing slash (e.g.,
'https://api.openai.com/v1/') and asserts the result is
'.../v1/chat/completions', and another test that passes a URL with an explicit
port (e.g., 'https://localhost:8080') and asserts the port is preserved in the
composed URI; locate the tests alongside the existing group that references
AskAiRepository.composeChatCompletionsUri and follow the same test structure and
expectations.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@test/ask_ai_repository_test.dart`:
- Around line 4-36: Add tests covering edge cases for trailing slashes and URLs
with ports to ensure AskAiRepository.composeChatCompletionsUri handles them
correctly; specifically, add one test that passes a base URL ending with a
trailing slash (e.g., 'https://api.openai.com/v1/') and asserts the result is
'.../v1/chat/completions', and another test that passes a URL with an explicit
port (e.g., 'https://localhost:8080') and asserts the port is preserved in the
composed URI; locate the tests alongside the existing group that references
AskAiRepository.composeChatCompletionsUri and follow the same test structure and
expectations.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 3a687081-22bb-4dab-adc2-eafa42e3b5a8

📥 Commits

Reviewing files that changed from the base of the PR and between bf03933 and ba0ee1f.

⛔ Files ignored due to path filters (15)

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📒 Files selected for processing (7)

• lib/data/provider/ai/ask_ai.dart
• lib/data/store/setting.dart
• lib/l10n/app_en.arb
• lib/l10n/app_zh.arb
• lib/l10n/app_zh_tw.arb
• lib/view/page/setting/entries/ai.dart
• test/ask_ai_repository_test.dart