docs: update ecosystem.md — missing 5 of 9 packages

[rororowyourboat]

Problem

docs/framework/ecosystem.md only lists 4 of 9 packages (gds-framework, gds-viz, gds-games, gds-examples). Missing: gds-stockflow, gds-control, gds-software, gds-business, gds-sim.

The dependency graph is also incomplete.

Options

1. Update the page with all packages and the full dependency graph
2. Redirect/replace with docs/index.md which already has the correct table — avoids maintaining two lists

Option 2 is recommended to prevent future drift.