refactor: consolidate CI and local dev orchestration (#108)

## Summary
- Extract shared bootstrap functions into `scripts/bootstrap-common.sh` (eliminates ~120 lines of duplicated forge/cast commands from e2e.yml)
- Create reusable `scripts/wait-for-service.sh` for health checks (replaces 60-line inline wait-for-stack)
- Merge dev and CI entrypoints into unified scripts branching on `CI` env var (delete `docker/ci-entrypoints/`)
- Replace 4 per-service CI Dockerfiles with parameterized `docker/Dockerfile.service-ci`
- Add `sync-tax-rates.mjs` to CI image builder stage
- Fix: CI now grants txnBot recenter access (was missing)
- Fix: txnBot funding parameterized (CI=10eth, local=1eth)
- Delete 5 obsolete migration docs and 4 DinD integration files

Net: -1540 lines removed

Closes #107

## Test plan
- [ ] E2E pipeline passes (bootstrap sources shared script, services use old images with commands override)
- [ ] build-ci-images pipeline builds all 4 services with unified Dockerfile
- [ ] Local dev stack boots via `./scripts/dev.sh start`

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: openhands <openhands@all-hands.dev>
Reviewed-on: https://codeberg.org/johba/harb/pulls/108

containers/landing-ci-entrypoint.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Minimal CI entrypoint for landing — just starts the dev server.
+set -euo pipefail
+cd /app/landing
+exec npm run dev -- --host 0.0.0.0 --port 5174