Major update of AI coach

[saksham2001]

Summary

Features

• Per-message tool-call traces in chat — expandable disclosure + live step-chain while generating
• Workouts logged from chat render the real workout card, tappable to workout detail
• Token & cost tracking per message/conversation (all providers; exact billed cost on OpenRouter) with ⓘ usage sheet in chat header
• Opt-in location + weather coach context (WeatherKit, city-level only, cached for background use) across chat, summary cards, and notifications
• Notification/summary variety: rotating coaching angles + prompt changes block
• Weather-aware check-ins that call out extreme conditions with a practical tip
• Compact context mode for the on-device Apple model (trimmed packet, short prompt, 4-turn history)
• Follow-up questions capped at 2 — single compact row on Today/Sleep cards, full-width wrapping rows in chat

Bug fixes

• Sleep summaries no longer generate from partial nights — gated on a full sync completing after the sleep session ends (with regeneration if late data grows the night); morning check-in waits for post-wake sync with an auto-retry
• Logging a workout for "today" without a start time failed any time before ~12:30pm (noon default rejected as ends-in-future): start now clamps back so the session ends at the current time
• On-device model truncated history mid-sentence — now drops whole oldest turns
• Weather fetch retried on every coach touchpoint after failure — added a 5-min cooldown
• Reduced gratuitous safety/data-quality note cards (null-by-default prompt rules; removed hardcoded notes from fallback responses)

Type of change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 📟 New / improved wearable support (BLE driver layer)
• 🤖 Coach / LLM change (tools, prompts, orchestration)
• 🎨 UI / DesignSystem change
• 🧹 Refactor / chore (no behavior change)
• 📝 Docs only
• ⚠️ Breaking change (existing data, settings, or APIs change)

How was this tested?

Tested on iPhone 16 Pro with Colmi R11

• Added / updated unit tests (PulseLoopTests)
• Ran the test suite locally (⌘U in Xcode)
• Tested on a physical device with a real ring — model:
• Tested with demo data (-seedDemo YES, no hardware)
• N/A (docs / non-code change)

Privacy & data

• This change does not send health data off-device without explicit user action.
• No secrets, API keys, or personal data are committed.
• N/A

Screenshots / recordings

Checklist

• My code follows the project's style (SwiftLint passes).
• I ran the tests and they pass.
• I updated docs / README where relevant.
• I read the Contributing guide.