AI prompt management dashboard and enhanced span inspectors.

Prompt management:

• Prompts list page with version status, model, override indicators, and 24h usage sparklines
• Prompt detail page with template viewer, variable preview, version history timeline, and override editor
• Create, edit, and remove overrides to change prompt content or model without redeploying
• Promote any code-deployed version to current
• Generations tab with infinite scroll, live polling, and inline span inspector
• Per-prompt metrics: total generations, avg tokens, avg cost, latency, with version-level breakdowns

AI span inspectors:

• Custom inspectors for ai.generateText, ai.streamText, ai.generateObject, ai.streamObject parent spans
• ai.toolCall inspector showing tool name, call ID, and input arguments
• ai.embed inspector showing model, provider, and input text
• Prompt tab on AI spans linking to prompt version with template and input variables
• Compact timestamp and duration header on all AI span inspectors

AI metrics dashboard:

• Operations, Providers, and Prompts filters on the AI Metrics dashboard
• Cost by prompt widget
• "AI" section in the sidebar with Prompts and AI Metrics links

Other improvements:

• Resizable panel sizes now persist across page refreshes
• Fixed <div> inside <p> DOM nesting warnings in span titles and chat messages