fix: unsafe string replacement when handling public paths

[onasilos]

What changed? Why?
replaced the unsafe .replace('public', '') with path.relative to ensure only the leading "public" folder is removed from paths. this prevents accidental removal of "public" appearing elsewhere in the string.

Notes to reviewers
logic now correctly handles all public image paths without affecting other parts of the path.

How has it been tested?
verified that post.publicImagePath resolves correctly for various paths, including edge cases where "public" appears mid-path.

BaseWeb

• base.org
• base.org/names
• base.org/builders
• base.org/ecosystem
• base.org/name/jesse
• base.org/manage-names
• base.org/resources

[vercel]

@onasilos is attempting to deploy a commit to the Coinbase Team on Vercel.

A member of the Team first needs to authorize it.

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1