fix: stabilize flaky E2E tests (browse-basic, ship-base-branch, dashboard-via)

browse-basic: bump maxTurns 5→7 (agent reads PNG per SKILL.md instruction)
ship-base-branch: extract Step 0 only instead of full 1900-line ship/SKILL.md
dashboard-via: extract dashboard section only + increase timeout 90s→180s

Root cause: copying full SKILL.md files into test fixtures caused context bloat,
leading to timeouts and flaky turn limits. Extracting only the relevant section
cut dashboard-via from timing out at 240s to finishing in 38s.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test/skill-e2e-bws.test.ts

@@ -45,7 +45,7 @@ describeIfSelected('Skill E2E tests', [
 4. $B screenshot /tmp/skill-e2e-test.png
 Report the results of each command.`,
       workingDirectory: tmpDir,
-      maxTurns: 5,
+      maxTurns: 7,
       timeout: 60_000,
       testName: 'browse-basic',
       runId,