Support embedded versions in YAML values (e.g., image tags)

[ChrisJBurns]

Summary

• Adds support for updating versions embedded within larger YAML values
• Uses the current version from VERSION file to find and replace just the version portion
• No new config fields needed - works automatically with existing prefix option

Example

For a value like:

toolhiveRunnerImage: ghcr.io/stacklok/toolhive/proxyrunner:v0.7.1

Config:

version_files:
  - file: values.yaml
    path: toolhiveRunnerImage
    prefix: "v"

Result after bump from 0.7.1 to 0.8.0:

toolhiveRunnerImage: ghcr.io/stacklok/toolhive/proxyrunner:v0.8.0

How it works

1. Reads the full value at the YAML path
2. Searches for prefix + currentVersion within the value
3. If found, replaces just that portion with prefix + newVersion
4. If not found, replaces the entire value (original behavior)

Test plan

• Added tests for embedded version in image tags
• Added tests for embedded version without prefix
• All existing tests updated and passing

🤖 Generated with Claude Code