The OpenRouterRouting interface only had only and order, but the runtime
passes the entire object as-is to the OpenRouter API's provider field.
This means all other fields worked at runtime but had no TypeScript
type-checking, no autocomplete, and no config validation.
This adds all fields from the OpenRouter provider selection API
(https://openrouter.ai/docs/guides/routing/provider-selection):
allow_fallbacks, require_parameters, data_collection, zdr,
enforce_distillable_text, ignore, quantizations, sort, max_price,
preferred_min_throughput, preferred_max_latency.
Also fixes the models.md documentation which had an invalid fallbacks
field in the example (not part of the OpenRouter API), replaces it with
a comprehensive example showing all available fields, and clarifies that
openRouterRouting is sent as-is in the provider field.
The current sandbox extension instructions state the glob configuration file must exist at `~/.pi/agent/sandbox.json` whereas it actually must exist at `~/.pi/agent/extensions/sandbox.json` to be picked up.
Sort resolved resources by precedence rank (project settings > project auto >
user settings > user auto > package) so first-wins collision logic produces
correct results. Also reorder CLI paths to prepend instead of append.
fixes#2781