feat(server): implement full REST API with JWT auth and real-time WebSocket

- Add HTTP handlers for issues, comments, agents, workspaces, inbox, members, and activity
- Implement JWT authentication middleware with Bearer token validation
- Add sqlc queries for all entities (CRUD operations)
- Extract router into reusable NewRouter() for testability
- Expand SDK with full API client methods (CRUD for all resources)
- Add updateWorkspace to SDK, add Member type to shared types

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/pkg/db/queries/member.sql

@@ -0,0 +1,33 @@
+-- name: ListMembers :many
+SELECT * FROM member
+WHERE workspace_id = $1
+ORDER BY created_at ASC;
+
+-- name: GetMember :one
+SELECT * FROM member
+WHERE id = $1;
+
+-- name: GetMemberByUserAndWorkspace :one
+SELECT * FROM member
+WHERE user_id = $1 AND workspace_id = $2;
+
+-- name: CreateMember :one
+INSERT INTO member (workspace_id, user_id, role)
+VALUES ($1, $2, $3)
+RETURNING *;
+
+-- name: UpdateMemberRole :one
+UPDATE member SET role = $2
+WHERE id = $1
+RETURNING *;
+
+-- name: DeleteMember :exec
+DELETE FROM member WHERE id = $1;
+
+-- name: ListMembersWithUser :many
+SELECT m.id, m.workspace_id, m.user_id, m.role, m.created_at,
+       u.name as user_name, u.email as user_email, u.avatar_url as user_avatar_url
+FROM member m
+JOIN "user" u ON u.id = m.user_id
+WHERE m.workspace_id = $1
+ORDER BY m.created_at ASC;