Inline Kitty graphics for math and Mermaid diagrams, interactive ask_question navigation, dedicated rule…

Introduces inline Kitty graphics rendering for LaTeX math and Mermaid diagrams in the artifact detail viewer with ASCII fallback and horizontal panning, interactive question navigation with write-in previews in ask_question, dedicated 20,000-token rule budgets to prevent customization eviction, and caps model retry backoff at 30 seconds, alongside plugin lifecycle hardening, Bubble Tea v2.0.9 upgrades, and headless background task logging.

• Added inline Kitty graphics rendering for LaTeX math equations ($$...$$ and fenced math, latex, and tex blocks) and Mermaid flowcharts and sequence diagrams in the artifact detail viewer, with Unicode ASCII fallback, Left/Right arrow horizontal panning for wide diagrams, and m to cycle between Image, ASCII, and Raw views.
• Improved the ask_question interactive prompt with Left/Right arrow navigation between questions, inline previews of confirmed write-in answers, check marks on answered options, and single-step submission on the final question.
• Improved the CLI startup banner for enterprise accounts to display the active Google Cloud Project ID beneath the signed-in account and plan tier.
• Improved model API retry responsiveness by capping per-attempt retry backoff at 30 seconds instead of waiting up to 4 minutes between attempts.
• Improved customization token budgeting by giving user and workspace rules a dedicated 20,000-token budget (cutting oversized rules on newline boundaries and listing over-budget rules by path and description) so large rule sets no longer evict skills, workflows, subagents, or MCP tools.
• Improved the /usage panel by removing the duplicate remaining-quota percentage line beneath each progress bar.
• Improved the default agent and subagent toolset by retiring the legacy find_by_name, grep_search, and list_dir tools from the default baseline while keeping them available to custom agents that explicitly list them in tools.
• Fixed plugin skill slash commands being double-prefixed (/:: ) when a skill's frontmatter name already includes the plugin prefix, or being shadowed when multiple plugins define skills with the same short name.
• Fixed plugin upgrades leaving old MCP server and sidecar processes running from deleted install directories, and pruned superseded plugin versions and staging directories from the marketplace cache on startup.
• Fixed disabled plugins disappearing from the /plugin list after enabled-only customization queries, and hardened plugin ID path validation on uninstall.
• Fixed terminal rendering and Kitty keyboard protocol stack handling on exit and screen clear by upgrading Bubble Tea to v2.0.9.
• Fixed headless (-p / --prompt) runs occasionally skipping the background-task waiting notice, logged background SDK tool progress to task log files, and reduced memory usage by cloning truncated command output previews.
• Fixed starting the CLI unpinning conversations or marking them unread in the desktop app.