* shell: add s3.accesskey.*, s3.anonymous.*, s3.serviceaccount.* commands
Add credential, anonymous access, and service account management commands:
Access key commands:
- s3.accesskey.create: add credentials to an existing user
- s3.accesskey.list: list access keys for a user (key ID + status)
- s3.accesskey.delete: remove a specific access key
- s3.accesskey.rotate: atomic create-new + delete-old key rotation
Anonymous access commands:
- s3.anonymous.set: set/remove public access on a bucket
- s3.anonymous.get: show anonymous access for a bucket
- s3.anonymous.list: list all buckets with anonymous access
Service account commands:
- s3.serviceaccount.create: create with optional action subset and expiry
- s3.serviceaccount.list: tabular listing, optionally filtered by parent
- s3.serviceaccount.show: detailed view of a service account
- s3.serviceaccount.delete: remove a service account
These replace the credential and anonymous portions of the monolithic
s3.configure and s3.bucket.access commands.
* shell: address review feedback for s3.accesskey.*, s3.anonymous.*, s3.serviceaccount.*
- Return flag parse errors instead of swallowing them (all commands)
- Add action validation in s3.anonymous.set (Read, Write, List, Tagging, Admin)
- Fix s3.serviceaccount.create output: note to use list for server-assigned ID
since CreateServiceAccountResponse does not return the ID
* shell: fix bucket matching and action validation in s3.anonymous.*
- Use SplitN instead of HasSuffix for bucket name matching to avoid
false positives when one bucket name is a suffix of another
- Make action validation case-insensitive with canonical normalization
* shell: fix nil panics, dedup actions, validate service account actions
- Fix nil-pointer panic in getOrCreateAnonymousUser when GetUser returns
err==nil with nil Identity (status.FromError(nil) returns nil status)
- Add nil Identity guards in s3.anonymous.get and s3.anonymous.list
- Deduplicate action values in s3.anonymous.set (e.g. -access Read,Read)
- Add action validation in s3.serviceaccount.create with case normalization
* shell: dedup actions and reject negative expiry in s3.serviceaccount.create
- Deduplicate -actions values (e.g. Read,read,Read produces one entry)
- Reject negative -expiry values instead of silently treating as no expiration
