feat: Better Web GUI with bot controls

[Mr-Tech-13]

Description

• replace the old web control page with a live matrix UI showing selected stores across the top and selected series on the left
• add runtime status tracking so each store/series cell reflects idle, checking, out_of_stock, in_stock, error, or unsupported
• add top-right filter menus for stores, series, and models, with changes applied to the running process
• persist filter changes back to the active dotenv file instead of keeping them in memory only
• add a settings gear modal to read and edit the full active dotenv file from the browser
• add an in-page restart control so config changes can be reloaded without manually stopping the process
• add configurable lookup concurrency with LOOKUP_THREADS
• add randomized lookup ordering with RANDOMIZE_LOOKUP_ORDER
• update matrix state behavior so the latest event wins and explicitly selected series render as idle instead of disappearing
• update project documentation to describe the live dashboard, WEB_PORT usage, persisted filter changes, restart flow, LOOKUP_THREADS, and RANDOMIZE_LOOKUP_ORDER
• clean up formatting and encoding regressions in touched files so lint and TypeScript compile succeed

Testing

• verified file-level integration by tracing the full flow between runtime control, web API, matrix state tracking, settings persistence, and UI actions
• verified that the new settings API updates LOOKUP_THREADS and RANDOMIZE_LOOKUP_ORDER in the running config
• verified that the matrix row generation now uses explicitly selected series when SHOW_ONLY_SERIES is set
• ran npm run lint
• ran npm run compile

New dependencies

• none