feat(kugetsu): add git server configuration management

Add 'kugetsu server' command for managing git server configurations:
- kugetsu server list              List all configured git servers
- kugetsu server add <name> <url>  Add a new git server
- kugetsu server remove <name>     Remove a git server
- kugetsu server default [<name>]   Get or set default server
- kugetsu server get [<name>]       Get URL for a server

Update get_repo_url() to use GIT_SERVERS config:
- First checks repos.json for direct mapping
- Then checks GIT_SERVERS for matching hostname
- Falls back to DEFAULT_GIT_SERVER
- Falls back to github.com as last resort

Update cmd_init to create config with default git servers:
- github.com -> https://github.com
- git.fbrns.co -> https://git.fbrns.co

Fixes #78

skills/kugetsu/scripts/kugetsu

@@ -139,6 +139,7 @@ issue_ref_to_branch_name() {
 
 get_repo_url() {
     local issue_ref="$1"
+    
     if [ -f "$REPOS_CONFIG" ]; then
         local url=$(python3 -c "import json, sys; d=json.load(open('$REPOS_CONFIG')); print(d.get('$issue_ref', ''))" 2>/dev/null || echo "")
         if [ -n "$url" ]; then
@@ -146,8 +147,20 @@ get_repo_url() {
             return
         fi
     fi
+    
     local instance=$(echo "$issue_ref" | cut -d'/' -f1 | cut -d'#' -f1)
     local rest=$(echo "$issue_ref" | sed 's/.*\///' | sed 's/#.*//')
+    
+    if [ -n "${GIT_SERVERS[$instance]:-}" ]; then
+        echo "${GIT_SERVERS[$instance]}/${rest}.git"
+        return
+    fi
+    
+    if [ -n "${GIT_SERVERS[$DEFAULT_GIT_SERVER]:-}" ]; then
+        echo "${GIT_SERVERS[$DEFAULT_GIT_SERVER]}/${rest}.git"
+        return
+    fi
+    
     echo "https://${instance}/${rest}.git"
 }
 
@@ -670,6 +683,100 @@ set_debug_mode() {
     echo "${filtered_args[@]}"
 }
 
+cmd_server() {
+    local action="${1:-}"
+    
+    case "$action" in
+        ""|"list")
+            if [ -z "${GIT_SERVERS+x}" ]; then
+                echo "No git servers configured"
+                return
+            fi
+            echo "Git servers:"
+            for key in "${!GIT_SERVERS[@]}"; do
+                local marker=""
+                if [ "$key" = "$DEFAULT_GIT_SERVER" ]; then
+                    marker=" (default)"
+                fi
+                echo "  $key -> ${GIT_SERVERS[$key]}$marker"
+            done
+            ;;
+        "add")
+            local name="${2:-}"
+            local url="${3:-}"
+            if [ -z "$name" ] || [ -z "$url" ]; then
+                echo "Usage: kugetsu server add <name> <url>" >&2
+                exit 1
+            fi
+            if grep -q "^GIT_SERVERS\[" "$KUGETSU_DIR/config" 2>/dev/null; then
+                sed -i "s|^GIT_SERVERS\[\"$name\"\]=.*|GIT_SERVERS[\"$name\"]=\"$url\"|" "$KUGETSU_DIR/config"
+                if ! grep -q "GIT_SERVERS\[\"$name\"\]" "$KUGETSU_DIR/config" 2>/dev/null; then
+                    sed -i "/^declare -A GIT_SERVERS/a GIT_SERVERS[\"$name\"]=\"$url\"" "$KUGETSU_DIR/config"
+                fi
+            else
+                echo "declare -A GIT_SERVERS" >> "$KUGETSU_DIR/config"
+                echo "GIT_SERVERS[\"$name\"]=\"$url\"" >> "$KUGETSU_DIR/config"
+            fi
+            source "$KUGETSU_DIR/config"
+            echo "Added git server: $name -> $url"
+            ;;
+        "remove"|"rm"|"delete")
+            local name="${2:-}"
+            if [ -z "$name" ]; then
+                echo "Usage: kugetsu server remove <name>" >&2
+                exit 1
+            fi
+            if [ -n "${GIT_SERVERS[$name]:-}" ]; then
+                if [ "$name" = "$DEFAULT_GIT_SERVER" ]; then
+                    echo "Error: Cannot remove default server. Set a new default first." >&2
+                    exit 1
+                fi
+                sed -i "/GIT_SERVERS\[\"$name\"\]/d" "$KUGETSU_DIR/config" 2>/dev/null
+                source "$KUGETSU_DIR/config"
+                echo "Removed git server: $name"
+            else
+                echo "Error: Server '$name' not found" >&2
+                exit 1
+            fi
+            ;;
+        "default")
+            local name="${2:-}"
+            if [ -z "$name" ]; then
+                echo "Current default: $DEFAULT_GIT_SERVER"
+                return
+            fi
+            if [ -n "${GIT_SERVERS[$name]:-}" ]; then
+                sed -i "s/^DEFAULT_GIT_SERVER=.*/DEFAULT_GIT_SERVER=\"$name\"/" "$KUGETSU_DIR/config"
+                source "$KUGETSU_DIR/config"
+                echo "Set default git server to: $name"
+            else
+                echo "Error: Server '$name' not found" >&2
+                exit 1
+            fi
+            ;;
+        "get")
+            local name="${2:-$DEFAULT_GIT_SERVER}"
+            if [ -n "${GIT_SERVERS[$name]:-}" ]; then
+                echo "${GIT_SERVERS[$name]}"
+            else
+                echo "Error: Server '$name' not found" >&2
+                exit 1
+            fi
+            ;;
+        *)
+            echo "Usage: kugetsu server <list|add|remove|default|get>" >&2
+            echo "" >&2
+            echo "Commands:" >&2
+            echo "  list              List all configured git servers" >&2
+            echo "  add <name> <url>  Add a new git server" >&2
+            echo "  remove <name>     Remove a git server" >&2
+            echo "  default [<name>]  Get or set default server" >&2
+            echo "  get [<name>]      Get URL for a server (default: current default)" >&2
+            exit 1
+            ;;
+    esac
+}
+
 cmd_init() {
     local force=false
 
@@ -694,6 +801,13 @@ cmd_init() {
 
 # Max concurrent dev agents (default: 3)
 # MAX_CONCURRENT_AGENTS=5
+
+# Git server configurations
+# Format: GIT_SERVERS["hostname"]="https://hostname"
+declare -A GIT_SERVERS
+GIT_SERVERS["github.com"]="https://github.com"
+GIT_SERVERS["git.fbrns.co"]="https://git.fbrns.co"
+DEFAULT_GIT_SERVER="github.com"
 EOF
         echo "Created config file: $KUGETSU_DIR/config"
     fi
@@ -1174,6 +1288,9 @@ main() {
         status)
             cmd_status
             ;;
+        server)
+            cmd_server "$@"
+            ;;
         doctor)
             cmd_doctor "$@"
             ;;