feat: rebrand QuestboardAI -> TaskFlow everywhere (UI, locales, index.html)

fix: subscription page - replace outdated content with real comparison table, fix gap layout

fix: sidebar gap layout bug, add active daily AI count display

Implement paywall modal, subscription pages, and translation keys

feat: rebrand PlotTwist to QuestboardAI

feat: rebrand TaskFlow to PlotTwist and align with Human-in-the-Loop AI Agent Proof-of-Work vision

Fix achievement and habit notification concurrency, suppress achievement alerts, and localized default name

feat: custom mixed habit intervals, unnamed habit localization, recharge notifications, and suppressed achievements notifications

feat: support granular mixed hours and minutes custom reset interval for habits

feat: implement universal custom habit reset intervals with dynamic formatting and unit options

feat: complete custom auto-reset interval support, high-frequency live tickers, and UI clean-up of manual datepicker

feat: integrate sketchy brain logo branding and add workspace agent guidelines

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