Add supported-chains cmd & Improve Error Messages

[ejacquier]

Supported Chains

• Added cre workflow supported-chains command (sorted alphabetically)

📊 Error Handling Improvements

#	Top Error (CSV)	Count	Improvement
1	no project settings file found	321	Now: clearer message ("no CRE project found") + suggests cre init, --project-root, or cd into project
2	Script not found "cre-compile"	303	Now: explains it comes from @chainlink/cre-sdk + suggests bun install / cre update
3	no RPC URLs found	178	Now: shows which target failed + suggests checking rpcs section and --supported-chains
4	failed to parse private key	159	Now: shows actual vs expected length (64 hex chars) + lists common mistakes
5	workflow.yaml: no such file or directory	155	Now: clearer message ("workflow settings file not found") + suggests cre workflow init or checking path

[github-actions]

👋 ejacquier, thanks for creating this pull request!

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[timothyF95]

Don't we have a generalised rpc check in the root of the cmd package?

[ejacquier]

Not quite. cmd/root.go has isLoadDeploymentRPC() which decides whether to load RPC settings (for deploy/pause/activate/delete). That's a
config-loading gate, not a validation error.

The merge-base changed after approval.

[github-actions]

⚠️ Abigen Fork Check - Update Available

The forked abigen package is outdated and may be missing important updates.

Version	Value
Current Fork	v1.17.0
Latest Upstream	null

Action Required

1. Review abigen changes in upstream (only the accounts/abi/bind directory matters)
2. Compare with our fork in cmd/generate-bindings/bindings/abigen/
3. If relevant changes exist, sync them and update FORK_METADATA.md
4. If no abigen changes, just update the version in FORK_METADATA.md to null

Files to Review

• cmd/generate-bindings/bindings/abigen/bind.go
• cmd/generate-bindings/bindings/abigen/bindv2.go
• cmd/generate-bindings/bindings/abigen/template.go

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⚠️ Note to PR author: This is not something you need to fix. The Platform Expansion team is responsible for maintaining the abigen fork.

cc @smartcontractkit/bix-framework