Rename skyhook-named directories and file names (agent/skyhook-agent, chart templates)

[lockwobr]

Summary

Directory and file names still carry skyhook. Purely internal, no user-visible behavior, but they keep the rename looking half-finished to anyone reading the tree.

Part of the rename tracked in #310. Lowest priority of the rename set. Deliberately filed separately so it does not get bundled into a change with real compatibility risk.

Surfaces

Source tree:

• agent/skyhook-agent/ (the Python package directory), and agent/skyhook-agent/src/skyhook_agent/ inside it

Chart templates:

• chart/templates/skyhook-crd.yaml
• chart/templates/cleanup-skyhooks-job.yaml

Operator source: file names such as skyhook_controller.go, skyhook_types.go. Note #375 already covers renaming Go identifiers; whether file names travel with it should be settled there rather than duplicated here.

Cautions

• zz.migration.*.go files must not be renamed or moved. They are hand-written one-shot migration shims despite the generated-looking prefix. See .claude/CLAUDE.md.
• Renaming the Python package directory touches build config (hatch), the Dockerfile, and CI paths. It is mechanical but not zero-risk, and it should not ride along with an unrelated change.
• The Python module name skyhook_agent is an import path. If anything outside this repo imports it, renaming is a break rather than a cleanup. Worth confirming before touching it, and it may be reasonable to rename the directory but keep the module.
• This is the kind of change that produces an enormous diff and hides real changes in review. Best done as its own PR, ideally right after a release rather than mid-cycle.

Acceptance criteria

• Decide whether the Python module skyhook_agent is renamed or only the containing directory
• Chart template files renamed, with helm template output verified unchanged
• Build, CI, and Dockerfile paths updated
• zz.migration.*.go files left alone
• Coordinated with Rename Skyhook-named Go identifiers to NodeWright (mechanical, no behavior change) #375 so file names and Go identifiers are not renamed twice
• Landed as a standalone PR