refactor: remove bal-pusher-enhanced and update docs/env

- Remove src/bin/bal-pusher-enhanced.rs (synchronous pusher variant)
- Remove bal-pusher.env and bal-pusher.sh from git tracking (now in .gitignore)
- Update all documentation to remove references to bal-pusher-enhanced:
  * 01_project_overview.md
  * 02_glossary_and_bitcoin_domain.md
  * 03_architecture_and_data_flow.md
  * 04_modules_detail.md
  * 05_api_reference.md (remove rawblock ZMQ section, update references)
  * 08_security_audit.md (remove references to bal-pusher-enhanced in DoS and ZMQ sections)
  * 09_references_and_links.md
- Build verified: cargo check passes for bal-pusher and bal-server binaries

docs/09_references_and_links.md

@@ -15,7 +15,7 @@
 | XPub/Address Derivation | `src/xpub.rs` | `parse_xpub`, `derive_address`, `get_descriptor`, BIP-84 |
 | HTTP Server | `src/bin/bal-server.rs` | Hyper + Tokio, routes, handlers, `pushtxs` logic |
 | Async Pusher | `src/bin/bal-pusher.rs` | ZMQ `hashblock`, RPC + Reqwest, `send_stats` |
-| Synchronous Pusher Enhanced | `src/bin/bal-pusher-enhanced.rs` | ZMQ `rawblock`, raw block header parsing, no `getblockchaininfo` |
+
 | Stats (broken) | `src/bin/bal-stats.rs.dontcompile` | Not compiled, incomplete HTML report generator |
 | Release script | `make_release.sh` | Hardcoded token, `cargo install` |
 | DB download script | `download_bal_db.sh` | `scp` from remote |
@@ -25,8 +25,7 @@
 | Utility scripts | `lib.sh` | Colored echo functions |
 | Contrib (install) | `contrib/download_and_install_bal.sh` | Nginx, Certbot, systemd setup, hardcoded xpub |
 | Contrib (install bitcoind) | `contrib/download_and_install_bitcoincore.sh` | Bitcoind download, GPG verify, systemd, config |
-| Contrib (install Tor) | `contrib/install_tor.sh` | Tor repository, `ControlPort 9051` | 
-| Systemd service | `bal-server.service` | Runs as `bal` user, `ProtectSystem`, `MemoryDenyWriteExecute` |
+| Contrib (install Tor) | `contrib/install_tor.sh` | Tor repository, `ControlPort 9051` || Systemd service | `bal-server.service` | Runs as `bal` user, `ProtectSystem`, `MemoryDenyWriteExecute` |
 | Systemd service | `bitcoind.service` | `zmqpubhashblock` setup |
 | Systemd service | `tbitcoind.service` | Testnet `bitcoind` |