Add player portal + character-sheet front end (phase 4 follow-up)

Turns the raw shard endpoints into proper, navigable pages in the site's visual
language.

- components/CharacterSheet.jsx: reusable sheet — attribute tiles, vitals bars,
  resistances, skills (with bars), and equipment — styled with the shared
  panel/grid vocabulary.
- Player portal with a nav bar: PlayerPortalLayout (Characters / Account tabs +
  sign-out) wraps /player and /account. /player (PlayerCharacters) tells the
  logged-in player if they haven't linked a game account (with the [link code
  prompt) or, once linked, shows their characters grouped by account; each
  character opens its sheet at /player/char/:serial. Account security moved into
  the same shell (the buried "Game accounts" block was removed from it).
  Login/register now land on /player.
- Public: GET /public/shard/online (redacted name+serial+map) drives an
  "Online now" list on /site/shard that links to public character sheets at
  /site/shard/char/:serial (ShardChar). Swagger: ShardOnlinePlayer + regenerated.
- api.shard.online added.

Verified live against the running shard: Darrow's full sheet (STR 120, 58
skills, 3 equipment) renders through the browser-facing proxy; the online list
returns the live roster; player routes 401 without a session.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011qPmpmVH1xGCiZoz9m9vW3

server/swagger/swagger-output.json

@@ -1410,6 +1410,33 @@
         }
       }
     },
+    "/api/v1/public/shard/online": {
+      "get": {
+        "tags": [
+          "Public · Shard"
+        ],
+        "summary": "Players online now (name + serial + map only)",
+        "description": "",
+        "responses": {
+          "200": {
+            "description": "Online players",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "array",
+                  "items": {
+                    "$ref": "#/components/schemas/ShardOnlinePlayer"
+                  }
+                }
+              }
+            }
+          },
+          "500": {
+            "description": "Internal Server Error"
+          }
+        }
+      }
+    },
     "/api/v1/public/shard/idoc": {
       "get": {
         "tags": [
@@ -10307,6 +10334,67 @@
           }
         }
       },
+      "ShardOnlinePlayer": {
+        "type": "object",
+        "properties": {
+          "type": {
+            "type": "string",
+            "example": "object"
+          },
+          "description": {
+            "type": "string",
+            "example": "A player online now (redacted for the public list)."
+          },
+          "properties": {
+            "type": "object",
+            "properties": {
+              "serial": {
+                "type": "object",
+                "properties": {
+                  "type": {
+                    "type": "string",
+                    "example": "string"
+                  },
+                  "example": {
+                    "type": "string",
+                    "example": "0x24C"
+                  }
+                }
+              },
+              "name": {
+                "type": "object",
+                "properties": {
+                  "type": {
+                    "type": "string",
+                    "example": "string"
+                  },
+                  "example": {
+                    "type": "string",
+                    "example": "Darrow"
+                  }
+                }
+              },
+              "map": {
+                "type": "object",
+                "properties": {
+                  "type": {
+                    "type": "string",
+                    "example": "string"
+                  },
+                  "nullable": {
+                    "type": "boolean",
+                    "example": true
+                  },
+                  "example": {
+                    "type": "string",
+                    "example": "Trammel"
+                  }
+                }
+              }
+            }
+          }
+        }
+      },
       "ShardHouse": {
         "type": "object",
         "properties": {