[-] fix --web-base-path deployments, closes #1328

[Syedowais312]

Description

Fix the embedded web UI so it loads correctly when --web-base-path is set.

Fixes #1328

The frontend build was generating root-relative asset URLs like /assets/ index-*.js. When pgwatch is served under a subpath such as /pgwatch/, the
browser requests /assets/... instead of /pgwatch/assets/..., which causes
the main bundle to 404 and leaves the page blank.

This change sets the Vite build base to a relative path so generated assets
resolve correctly under both root and subpath deployments.

AI & Automation Policy

• [ ✔️] I am the human author and take full personal responsibility for every change in this PR.
• No AI or automated generative tool was used in any part of this PR OR I have disclosed all tool(s) below.

AI/automation tools used (leave blank if none):

Checklist

• [ ✔️] Code compiles and existing tests pass locally.
• New or updated tests are included where applicable.
• Documentation is updated where applicable.

[coveralls]

Coverage Report for CI Build 24198664038

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage decreased (-0.08%) to 83.408%

Details

• Coverage decreased (-0.08%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• 4 coverage regressions across 1 file.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

4 previously-covered lines in 1 file lost coverage.

File	Lines Losing Coverage	Coverage
internal/reaper/reaper.go	4	37.04%

---

Coverage Stats

Relevant Lines:	5322
Covered Lines:	4439
Line Coverage:	83.41%
Coverage Strength:	0.95 hits per line

---

💛 - Coveralls