Change default port from 8080 to 7334 (NGIT on phone keypad)

- Update default bind address in src/config.rs to 127.0.0.1:7334
- Update all four critical config sources per AGENTS.md:
  - src/config.rs (code default and tests)
  - .env.example (development template)
  - docs/reference/configuration.md (user documentation)
  - nix/module.nix (NixOS deployment)
- Update all documentation examples and references:
  - README.md (with note about phone keypad mnemonic)
  - docs/how-to/*.md (deploy, prometheus-setup, test-compliance)
  - docs/explanation/*.md (architecture, comparison)
  - docs/learnings/grasp-audit.md

Port 7334 spells NGIT on a phone keypad, making it memorable and
project-specific.

All tests pass (336 lib tests + 51 integration tests).

1 files changed, 2 insertions, 2 deletions

diff --git a/docs/how-to/test-compliance.md b/docs/how-to/test-compliance.md
index 370fb9a..8aa7ab1 100644
--- a/docs/how-to/test-compliance.md
+++ b/docs/how-to/test-compliance.md
@@ -184,7 +184,7 @@ nix develop -c cargo run
 
 # In another terminal, run audit tool
 cd grasp-audit
-nix develop -c cargo run -- --url ws://127.0.0.1:8080
+nix develop -c cargo run -- --url ws://127.0.0.1:7334
 ```
 
 ### For CI/CD
@@ -424,7 +424,7 @@ nix develop -c cargo test --test nip01_compliance --test nip34_announcements
 **For deep compliance check:**
 ```bash
 cd grasp-audit
-nix develop -c cargo run -- --url ws://127.0.0.1:8080
+nix develop -c cargo run -- --url ws://127.0.0.1:7334
 ```
 
 **Key points:**