chore: generate examples from the canonical OpenAPI document

[ChiragAgg5k]

Summary

appwrite/specs now publishes one open-api3-<version>.json per current version (appwrite/specs#105, #106), and the generator has selected its platform from that document since 4.8.0. The per-platform OpenAPI 3 files are being removed for 2.0.x and latest, so example.php fetches the canonical file. Swagger 2 documents remain per platform and that path is unchanged. AGENTS.md and README updated to match.

Validation

• php example.php web console and php example.php node server against the published canonical document: generation succeeds; the Node server example for account.get configures setSession() and the Web console example configures the project only, matching the previous per-platform output.

Related to CLO-4377.

[greptile-apps]

Greptile Summary

The PR updates example generation to consume the canonical OpenAPI 3 document while retaining platform-specific Swagger 2 URLs and explicitly selecting the SDK platform.

• Documents the canonical specification URL and platform-selection behavior.
• Adds the missing setPlatform() call to the README example.
• Adds a bounded Rust encoding_rs dependency.

Confidence Score: 5/5

The PR appears safe to merge, with no outstanding correctness or repository-rule violations identified.

The README now passes the selected platform to the SDK, resolving the previously identified platform-filtering problem. That thread was manually resolved without explanation.

Important Files Changed

Filename	Overview
example.php	Fetches canonical OpenAPI 3 specifications while preserving platform-specific Swagger 2 fetching.
README.md	Documents canonical specification usage and now explicitly configures the selected SDK platform.
AGENTS.md	Updates contributor guidance for canonical OpenAPI 3 and platform-specific Swagger 2 URLs.
templates/rust/Cargo.toml.twig	Adds a bounded encoding_rs dependency to generated Rust SDK manifests.

_{Reviews (3): Last reviewed commit: "docs: select the platform in the README ..." | Re-trigger Greptile}