fix(mounts): normalize volume field casing to lowercase with backward compatibility

[madejackson]

Disclaimer

This PR was written with the help of Plurality (using model kimi 2.6)

I manually checked the code. It seems legit and should not rise any new issues. Nevertheless I am running this version of Cosmos Cloud on my nodes to catch potential issues asap.

There is one line I'm not sure we should leave in the code or not:

Cosmos-Server/client/src/pages/servapps/containers/volumes.jsx

Line 114 in be4c720

ReadOnly: false, // TODO: add support for this

Update: this gets addressed here: #599

Summary

Fixes the inconsistency where Volume Target and Source were the only fields using uppercase (Type, Source, Target) while every other runtime variable in Cosmos uses lowercase (type, source, target).

Problem

• Market templates and Docker Compose imports use lowercase field names (source, target, type) — this is the Docker Compose spec convention.
• Runtime container operations (create, update, export) used the raw Docker SDK mount.Mount struct, which serializes with uppercase Go exported fields (Source, Target, Type).
• This caused the frontend to juggle two casing conventions depending on whether a volume came from a template, a compose file, or an inspected running container.

Solution

Introduced a Cosmos-local CosmosMount type with lowercase JSON tags and bidirectional conversion helpers:

Before	After
[]mount.Mount ({"Type":"bind","Source":"/x","Target":"/y"})	[]CosmosMount ({"type":"bind","source":"/x","target":"/y"})

Key changes

• New type: src/docker/mount.go — CosmosMount with lowercase tags and helper methods:
  • ToDockerMount() / ToDockerMountSlice() — send to Docker SDK
  • FromDockerMount() / FromDockerMountSlice() — receive from Docker SDK
  • UnmarshalJSON() — accepts both lowercase and uppercase on input
• Backend structs updated:
  • ContainerCreateRequestContainer.Volumes → []CosmosMount
  • ContainerForm.Volumes → []CosmosMount (JSON tag changed from Volumes → volumes)
• Conversion points: CreateService(), UpdateContainerRoute(), ExportContainer() now convert at the Docker SDK boundary.
• Frontend updated: volumes.jsx, docker-compose.jsx, newServiceForm.jsx use lowercase fields exclusively.

Backward Compatibility

The custom UnmarshalJSON on CosmosMount accepts both casing styles on input:

// Lowercase (new canonical) — ✅ works
{"type":"bind","source":"/host","target":"/cont"}

// Uppercase (legacy Docker SDK) — ✅ still works
{"Type":"volume","Source":"myvol","Target":"/data"}

Serialization always outputs lowercase, so clients and generated SDKs will gradually migrate without breaking.

Testing

• go build ./src/docker/... and go build ./src/... pass
• Verified lowercase input → correct parsing
• Verified uppercase input → correct parsing (backward compat)
• Verified serialization → always lowercase

---

Checklist

• Branch targets unstable
• Go code builds cleanly
• Backward compatibility preserved for API consumers
• Frontend volume flows updated (import, create, update, export)

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[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Cosmos Developer.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email email@example.com
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails