TradingView Alert System in PineScript

I need a single, well-structured Pine Script that turns TradingView into a full alert engine for my multi-asset watchlist. The script must:

• Cover stocks, forex, and cryptocurrency charts without manual edits when I switch symbols.
• Trigger three alert types from the same code base:
– Price level crosses (static or dynamic levels I define in inputs).
– Indicator-based events (for example, moving-average crossovers or RSI thresholds—please expose these as adjustable settings).
– Fully custom logical conditions I can toggle on or off in the user menu.
• Publish alerts through TradingView’s native “Create Alert” dialog so I can choose Webhook, SMS, or pop-up delivery on the platform side.

Acceptance criteria
1. A single .pine file that compiles on the current Pine Script version.
2. Clean, commented code showing where to adjust levels, indicator parameters, and custom logic.
3. A brief set-up guide that walks me through adding the script to a chart and creating an alert template.
4. Successful test: alerts must fire correctly on a live chart session for one stock, one forex pair, and one crypto pair.

All chart logic should remain efficient to avoid the dreaded “execution timeout” on lower-end devices. If any built-in TradingView functions will simplify maintenance, feel free to use them, but keep external dependencies to zero.