Fixed code clarity and improved performance.

Major update since version 0.5.

• Simplified history handling to two modes:
- Recent N: keeps only a bounded recent part of the conversation active, with a “Load previous” button for older messages.
- Auto window: automatically loads older history when scrolling to the top.

• Improved performance for very long ChatGPT conversations by trimming old conversation graph state before ChatGPT’s page code processes it.

• Added logical Recent-N counting so long sequences of assistant progress/tool activity do not unnecessarily consume the whole recent-message budget.

• Added bounded virtualization for loaded older history. Older pages can be loaded without allowing the DOM to grow indefinitely; only a small number of archived pages remain mounted at once.

• Greatly improved the appearance of loaded older messages. AntiCurse now follows the current ChatGPT message width, margins, user bubbles, assistant formatting, Markdown styling, and responsive layout.

• Improved rendering of agent/tool activity. Raw serialized tool calls and “[Non-text visible message]” placeholders are no longer dumped into the conversation. Recognized tool activity is shown as compact ChatGPT-style activity rows instead.

• Added local conversation backup and Markdown export with Clean, Progress, and Full detail levels. Progress is the default export level.

• Improved Markdown exports by removing empty assistant sections and rendering task plans as readable checklists.

• Fixed Firefox popup sizing.

• Fixed multiple Chromium startup/history-delivery races that could prevent Auto Window or the Load Previous button from working.

• Fixed startup races in Firefox and Chromium that could temporarily use the wrong history mode or message limit.

• Added extensive automated tests, including real Chromium and Firefox WebExtension tests for conversation trimming, history loading, virtualization, and visual fidelity.

All conversation processing and backup storage remain local to the browser.