docs: Add warning for key format issue

[dknopik]

Issue Addressed

• Quick and dirty warning for Allow pubkey and pubKey in encrypted_private_key.json #712

Proposed Changes

To avoid user confusion and to provide a workaround, give a short explanation in the docs until a fix is released in a stable version.

[claude-code-actions-sigp]

Claude finished @dknopik's task —— View job

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Code Review Complete

Tasks

• Read the modified documentation file
• View the PR diff to see exact changes
• Understand context from issue Allow pubkey and pubKey in encrypted_private_key.json #712
• Review documentation quality and clarity
• Provide comprehensive feedback

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Review Summary

This PR adds a helpful warning to the migration documentation about a key format compatibility issue between go-ssv and Anchor. The documentation change is clear and actionable.

Detailed Review

Documentation Quality ✅

The warning is well-placed in the migration guide where users would naturally encounter the issue. The message clearly:

• Describes the error message users will see
• Provides the exact fix (change "pubkey" to "pubKey")
• Sets expectations that this is temporary until a proper fix is released

Technical Accuracy ✅

I verified the underlying code in anchor/common/operator_key/src/encrypted.rs:55 which shows:

#[serde(rename = "pubKey")]
pubkey: Option<String>,

Anchor expects pubKey (camelCase) as per the serde rename directive. The warning accurately reflects this requirement.

Suggestions for Improvement

1. Add file path reference
The warning could be more specific about which file to modify:

-If Anchor fails to start with the message `Unable to parse key: unknown field pubkey, expected one of pubKey (...)`, please change "pubkey" to "pubKey" in the encrypted_private_key.json file.
+If Anchor fails to start with the message `Unable to parse key: unknown field pubkey, expected one of pubKey (...)`, please change `"pubkey"` to `"pubKey"` in your `encrypted_private_key.json` file (typically located at `~/.anchor/<network>/encrypted_private_key.json`).

2. Consider mentioning the root cause
For transparency, you might add a brief note about why this happens:

:::warning
If Anchor fails to start with the message `Unable to parse key: unknown field pubkey, expected one of pubKey (...)`, this indicates the key file uses an older format from go-ssv. Please change `"pubkey"` to `"pubKey"` in your `encrypted_private_key.json` file. This compatibility issue will be fixed in a future release.
:::

3. Minor formatting improvement
The backticks around "pubkey" and "pubKey" help distinguish them as JSON keys rather than general terms. Consider also wrapping the filename similarly.

Overall Assessment

Approve with minor suggestions. This is a valuable addition that will prevent user confusion during migration. The warning:

• ✅ Addresses a real user pain point (issue Allow pubkey and pubKey in encrypted_private_key.json #712)
• ✅ Provides clear, actionable guidance
• ✅ Is appropriately marked as temporary
• ✅ Uses proper MDX warning syntax
• ✅ Is placed in the correct location in the migration guide

The suggestions above are optional enhancements - the PR is good to merge as-is if you prefer to keep it minimal.

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[dknopik]

the PR is good to merge as-is if you prefer to keep it minimal.

👍 , wdyt?