feat(usage): implement limit optimization and session planning features

[amitashwinibhagat]

Description

This PR implements the Limit Optimization feature set, giving users actionable guidance for staying within Claude usage limits across Claude.ai, Claude Code, and Claude Cowork. It adds a 21-tip contextual recommendation system, a Session Overlap Planner for managing the 5-hour rolling window, and read-only Claude Code diagnostics. All new user-facing strings are localized across 13 languages, and comprehensive unit tests cover the new calculation and recommendation logic.

Changes

Models

• LimitOptimizationTip — Catalog of 21 tips across Claude.ai (9), Claude Code (8), and Claude Cowork (4) categories, with metadata for action style, risk level, and sort order
• SessionPlanningSettings — Profile-scoped settings for the Session Overlap Planner, including planned work start time, typical time-to-limit, auto-estimation toggle, ping mode (reminder vs auto-send), waste warnings, and plan-mode tips. Backward-compatible decoding for profiles without this field
• SessionLimitObservation — Records high-usage observations per reset window for auto-estimation

Services

• LimitOptimizationTipService — Recommendation engine that ranks tips based on session percentage, peak hours, MCP configuration, and proximity to limit. Supports rotating contextual tips
• SessionPlanningService — Runtime loop (60s interval) that computes recommended ping times, deduplicates reminders, records observations at ≥90% usage, and optionally auto-sends dummy prompts. Clears one-off plans after execution
• ClaudeCodeOptimizationService — Read-only diagnostics for MCP server count, CLAUDE.md size, and settings entries. Provides copyable checklist items (/context, /clear, /compact, /rewind) and a session handoff template

UI Components

• SessionPlanningSettingsView — Settings card with educational copy about 5-hour windows, time picker, duration slider with auto-estimation, ping mode toggle, and live recommendation display with quick actions
• LimitOptimizationGuideView — Full guide with category-filtered tip cards showing action-style and risk-level badges, with copy buttons for actionable commands
• LimitHygieneCard — Claude Code settings card showing diagnostics, expandable "Before You Prompt" checklist, and copyable handoff template
• SessionOverlapCard — Menu bar popover card displaying active session state or next planned ping time
• ContextualTipCard — Rotating actionable tip in the popover based on current usage

Updated Existing Components

• Profile / ProfileManager — Added sessionPlanningSettings field with backward compatibility and update methods
• AutoStartSessionService — Extracted public startSession(for:source:) for planned overlap use; replaced hardcoded "Hi" with Constants.SessionPlanning.dummyPrompt
• NotificationManager — Added session overlap reminder, planned ping success, and waste warning notifications
• MenuBarManager — Integrated SessionPlanningService start/stop and recordUsage calls
• FormatterHelper — Added timeString(from:) helper
• PopoverContentView — Added SessionOverlapCard and ContextualTipCard
• GeneralSettingsView — Added SessionPlanningSettingsView and guide navigation link
• ClaudeCodeView — Added LimitHygieneCard

Localization

• Added 90+ new keys to en.lproj/Localizable.strings and all 12 non-English locales with English fallbacks
• All localization files pass validation (scripts/validate_localizations.sh)

Tests

• SessionPlanningServiceTests — Lead time calculations, ping timing, day boundaries, duration clamping, backward-compatible decoding
• LimitOptimizationTipServiceTests — Catalog completeness (21 tips), recommendation engine logic, rotating tips, actionable filtering
• ClaudeCodeOptimizationServiceTests — Checklist items, template content, diagnostics thresholds, read-only behavior verification

Important Guidelines

• Do NOT use App Groups Keychain with app group identifiers. This app is distributed outside the App Store via a Developer ID certificate. App Group entitlements require Keychain access prompts on every launch, which breaks the user experience. Use standard UserDefaults and standard Keychain access (without group identifiers) instead.
• Follow existing code patterns and architecture (MVVM, protocol-oriented)
• Add localization keys for any new user-facing strings (9 languages supported)
• Test on macOS 14.0+ (Sonoma)

Checklist

• I have tested these changes on a running build
• I have attached screenshots/recordings for any visual changes (REQUIRED — see Screenshots section above)
• I have not introduced App Group or grouped Keychain usage
• I have added localization keys for any new user-facing strings (90+ keys added to all 13 locales)

[dan-orth]

Thanks for doing this –– looks like it would be very helpful!