fix: show save button in VRL snippet form

[TerrifiedBug]

Summary

• Hide snippet list when creation/edit form is open so Cancel/Create buttons are visible
• The overflow-hidden container was clipping the buttons below the max-h-64 boundary

Test plan

• Click + to open snippet form, verify Cancel/Create buttons are visible
• Fill in name + code, click Create, verify snippet is saved
• Click Cancel, verify snippet list reappears

[greptile-apps]

Greptile Summary

This PR fixes a long-standing UX bug in the VRL snippet drawer where the Cancel/Create buttons were invisible because the max-h-64 overflow-hidden container clipped content below the fold. The fix is clean: the height constraint is removed when showForm is true, and the snippet list (ScrollArea) is unmounted while the form is open so both panels never compete for the same constrained space.

The PR also bundles two legitimate improvements:

• Environment selector (environment-selector.tsx): new handleEnvironmentChange redirects users from detail pages (e.g., /pipelines/<id>) back to the corresponding list page when they switch environments, preventing stale detail views.
• Pipelines page + dashboard router: Math.max(0, ...) added to both the frontend getReductionPercent helper and the server-side stats query to prevent negative reduction values being displayed for amplifying pipelines.
• CI/workflows: Agent image dev-build version now includes short SHA (dev-${GITHUB_SHA::7}), consistent with the dev-binaries job for easier build correlation.

Confidence Score: 5/5

• This PR is safe to merge — it's a focused UI fix with no security, data integrity, or API contract implications.
• All changes are purely presentational (height constraint / conditional rendering) or cosmetic number-clamping. No new tRPC procedures, no schema changes, no mutations added, and no middleware is bypassed. The environment selector redirect only pushes to hardcoded paths. No files require special attention.
• No files require special attention

Important Files Changed

Filename	Overview
src/components/flow/vrl-snippet-drawer.tsx	Core fix: conditionally removes max-h-64 overflow-hidden when the form is open and unmounts ScrollArea while the form is visible, ensuring Cancel/Create buttons are never clipped. Logic is correct.
src/components/environment-selector.tsx	Adds handleEnvironmentChange to redirect users from detail pages back to their list page when the environment is switched. Implementation is functionally correct and prevents stale detail views.
src/app/(dashboard)/pipelines/page.tsx	Clamps getReductionPercent to a minimum of 0 to prevent negative display values for amplifying pipelines; purely presentational fix with no logic regressions.
src/server/routers/dashboard.ts	Mirrors the frontend clamping change server-side in the stats procedure; correctly guarded by withTeamAccess("VIEWER") middleware and no new procedures are introduced.
.github/workflows/ci.yml	Agent image dev-build version appends the short SHA (dev-${GITHUB_SHA::7}), improving build correlation with the dev-binaries job.

_{Last reviewed commit: 35bbe81}