feat(thin): reconcile post-ready ThinRuntime FUSE template updates

[jlon]

Background

ThinRuntime exposes FUSE template fields such as resources, image, lifecycle, environment, and options. The initial transform correctly renders FUSE resources, but post-ready changes are not reconciled.

pkg/ddc/base/syncs.go invokes Implement.SyncRuntime() on every reconciliation. pkg/ddc/thin/sync_runtime.go currently returns (false, nil) unconditionally, so an updated ThinRuntime never refreshes its values ConfigMap or FUSE DaemonSet.

Reproduction

1. Create a Dataset and ThinRuntime with a FUSE resource request.
2. Wait until the ThinRuntime is Ready.
3. Apply a changed spec.fuse.resources (for example CPU request 1 to 4), or change a FUSE template field such as image/lifecycle.
4. Observe the runtime values ConfigMap and FUSE DaemonSet.

Actual behavior

Neither the values ConfigMap nor the DaemonSet template changes. Operators must patch the generated DaemonSet manually, which is not a declarative or durable interface.

Expected behavior

ThinRuntime should reconcile supported post-ready FUSE template fields into the rendered values and DaemonSet. For an OnDelete DaemonSet, the controller should update the template but must not silently delete active FUSE Pods; rollout semantics should be documented or surfaced in status/events.

Proposed direction

1. Implement ThinEngine SyncRuntime() using the existing Thin transform/values machinery and only update resources when the rendered desired state differs.
2. Cover at least resources, image, and lifecycle with controller tests.
3. Add an end-to-end test: update a ready ThinRuntime and assert that its values ConfigMap and DaemonSet template converge.

Scope note

This request does not claim that Fluid can migrate old Linux FUSE file descriptors after a FUSE Pod exits. CSI FuseRecovery restores the consumer mount path for newly opened files; existing fd recovery is an application/runtime boundary.

Tested version

Fluid commit a6d461c7, using a Generic CacheRuntime ThinRuntime integration.