fix: skip update-available check for dev versions

[TerrifiedBug]

Summary

• Agents running dev-tagged Docker images report "dev" as their version
• isVersionOlder("dev", "0.1.2") produced undefined behavior due to NaN from "dev".split(".").map(Number)
• Explicitly return false when either version is "dev" so the fleet page doesn't show "Update available" for dev agents

Test plan

• Run dev-tagged agent image, verify no "Update available" badge on fleet page
• Run released agent image older than latest, verify badge still appears

[greptile-apps]

Greptile Summary

Fixes undefined behavior in version comparison when agents report "dev" as their version string. The isVersionOlder() function now explicitly returns false when either version is "dev", preventing NaN results from "dev".split(".").map(Number) and stopping spurious "Update available" badges from appearing on the fleet page for development builds.

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• Single-line fix that addresses a specific edge case with clear intent. The change is minimal, well-scoped, and prevents undefined behavior without affecting normal version comparisons. No breaking changes or side effects.
• No files require special attention

Important Files Changed

Filename	Overview
src/lib/version.ts	Added early return for "dev" versions to prevent NaN from string-to-number conversion

_{Last reviewed commit: c042aa4}