fix(ci): build Hypatia escript from repo root (estate dogfood drift)

The hypatia repo dropped its scanner/ subdirectory; mix.exs now lives at
the repo root. The dogfood build step still did `cd scanner`, failing with
"cd: scanner: No such file or directory" and red-flagging every PR.
Build from the checkout root instead. Idempotent estate sweep.

Refs verisimiser#59

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

k9-svc/editors/vscode/.github/workflows/static-analysis-gate.yml

@@ -145,7 +145,6 @@ jobs:
           if [ -d "$HOME/hypatia/scanner" ]; then
             cd "$HOME/hypatia"
             if [ ! -f hypatia-v2 ]; then
-              cd scanner
               mix deps.get
               mix escript.build
               mv hypatia ../hypatia-v2
@@ -326,4 +325,4 @@ jobs:
 
           Findings saved as \`unified-findings\` artifact.
           The gitbot-fleet scanner will ingest these on its next pass.
-          EOF
+          EOF