feat(cli): render config improvements

[dhfang]

• new --populate-config flag writes the result to the config file. Without --yes it prints the config it would write, lists what that changes, and asks before writing.
• Default output is now the whole config, the existing one with the settings for relaying between the two chains added, rather than a fragment to copy-paste.

closes fou-1473

[greptile-apps]

Greptile Summary

The PR changes deploy render-config to merge deployment-derived settings into the complete existing configuration and optionally persist it after confirmation.

• Adds typed merging and conflict reporting for chains, connections, and attestors.
• Keeps rendered YAML on stdout while directing interactive and status output to stderr.
• Adds --populate-config, documentation, and merge-focused tests.

Confidence Score: 4/5

The PR is not yet safe to merge because population can successfully overwrite the config with an undeclared chain that lacks its required RPC endpoint.

The attempted fix validates only after writing and treats validation failure as a warning, so the previously reported incomplete-chain configuration remains persisted and unusable.

Files Needing Attention: cli/cmd/ibc/deploy.go, cli/cmd/ibc/deploy_test.go

Important Files Changed

Filename	Overview
cli/cmd/ibc/deploy.go	Implements preview, confirmation, and persistence, but still stores an invalid incomplete-chain configuration before validating it.
cli/internal/config/patch.go	Adds identity-based replacement and conflict reporting for projected configuration sections.
cli/cmd/ibc/main.go	Registers the population flag with wording that now matches the print-and-write behavior.
cli/cmd/ibc/deploy_test.go	Updates render tests but preserves the undeclared-chain case with an empty required RPC endpoint.
cli/internal/config/patch_test.go	Covers append, replacement, idempotency, and attestor identity behavior.
docs/6-ibc-cli/6-cli-commands.md	Updates generated command documentation for the full-config output and population flag.

_{Reviews (2): Last reviewed commit: "report populate status on stderr and war..." | Re-trigger Greptile}

[dhfang]

@greptile re-review

[linear-code]

FOU-1473