ChemSearch v1.9.0 - Major UI refresh, More AI providers & color schemes etc.

What's New

• Major Search UI Refresh: The main search and compound result pages have been redesigned with a cleaner blue-first layout, improved spacing, better summary cards, and more user-friendly placement for key actions.
• Expanded AI Providers: AI descriptions now support OpenAI, OpenRouter, and Mistral AI along with Google Gemini and Groq Cloud.
• AI Model Selection: Settings now include a provider dropdown, model dropdown, default models, and a Refresh models action after adding an API key.
• Color Schemes: Added selectable app color schemes: Blue, Violet, Emerald, Rose, and Amber.
• Progressive Synonym Loading: Synonyms now load in batches of 10 with Show 10 more and Collapse controls, making large PubChem synonym lists much faster to browse.
• Secure API Key Storage: API keys are now stored using Android Keystore-backed encryption.

Improvements & Fixes

• Turned quick compound info (CID, CAS and Molecular Weight) into chips.
• Molecular weight is now labeled as MW (g/mol) while keeping the displayed value readable on small screens.
• The Find isomers action now sits directly beside the molecular formula for faster formula-based searching.
• Added a 'Share' feature in main search results page top the top right of the 2D/3D structure viewer.
• Settings export/import now includes API keys and recent AI provider/model settings.
• Network security has been tightened by disabling cleartext traffic.

Technical Changes

• Added SecurePrefs for Android Keystore-backed AES/GCM encryption of API keys.
• Added model-list API support for Gemini and OpenAI-compatible providers.
• Expanded AiProvider and AI model catalog state to support provider defaults, selected models, refresh status, and refresh errors.
• Updated AI description generation to use the selected provider model instead of fixed hardcoded model names.
• Refactored settings UI around dropdown-driven AI provider and model controls.
• Consolidated theme color handling into the app theme layer with selectable accent schemes.
• Updated settings backup format to version 2 with app version metadata and API key export/import support.