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).

3 files changed, 6 insertions, 6 deletions

diff --git a/docs/how-to/deploy.md b/docs/how-to/deploy.md
index 6fe8776..157e5f8 100644
--- a/docs/how-to/deploy.md
+++ b/docs/how-to/deploy.md
@@ -229,7 +229,7 @@ git ls-remote https://ngit.example.com/<npub>/<repo>.git
 
 ### Network
 - `bindAddress` - IP to bind to (default: "127.0.0.1")
-- `port` - Port to listen on (default: 8080)
+- `port` - Port to listen on (default: 7334)
 
 ### Storage
 - `dataDir` - Base directory for data (default: /var/lib/ngit-grasp-{name})
diff --git a/docs/how-to/prometheus-setup.md b/docs/how-to/prometheus-setup.md
index 741255b..53ec480 100644
--- a/docs/how-to/prometheus-setup.md
+++ b/docs/how-to/prometheus-setup.md
@@ -13,7 +13,7 @@ This guide shows how to configure Prometheus and Grafana to monitor ngit-grasp.
 First, verify that ngit-grasp is exposing metrics:
 
 ```bash
-curl http://localhost:8080/metrics
+curl http://localhost:7334/metrics
 ```
 
 You should see Prometheus-formatted metrics like:
@@ -41,7 +41,7 @@ services.prometheus = {
     {
       job_name = "ngit-grasp";
       static_configs = [{
-        targets = [ "localhost:8080" ];  # ngit-grasp bind address
+        targets = [ "localhost:7334" ];  # ngit-grasp bind address
       }];
       scrape_interval = "15s";
       metrics_path = "/metrics";
@@ -105,7 +105,7 @@ global:
 scrape_configs:
   - job_name: 'ngit-grasp'
     static_configs:
-      - targets: ['host.docker.internal:8080']  # or your ngit-grasp host
+      - targets: ['host.docker.internal:7334']  # or your ngit-grasp host
     metrics_path: /metrics
 ```
 
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:**