feat(clients): add nim-allographer client with BaraDB driver support

- Pure Nim wire protocol client (async + sync, no C FFI)
- Query Builder: fluent API, SQL generator, execution, transactions
- Schema Builder: create/alter/drop tables, column operations
- Connection pool with aging and timeout handling
- ORM integration via compile-time DB_BARADB switch
- Tests: test_open, test_query
- Documentation: README.md, PLAN_BARADB.md

clients/nim-allographer/example/database/seeder/data/post_seeder.nim

@@ -0,0 +1,32 @@
+import std/json
+import std/strformat
+import std/asyncdispatch
+import std/oids
+import std/times
+import ../../../../src/allographer/query_builder
+import ../../connection
+import ../../schema
+
+proc postSeeder*() {.async.} =
+  seeder(rdb, "post"):
+    let postCount = rdb.table("post").count().await
+    if postCount > 0:
+      return
+
+    let users = rdb.table("user").get().orm(UserTable).await
+    if users.len == 0:
+      raise newException(ValueError, "No users found in database")
+
+    var postList: seq[JsonNode]
+    for i in 1..users.len:
+      let row = PostTable(
+        id: $genOid(),
+        title: &"post {i}",
+        content: &"content {i}",
+        user_id: users[i-1].id,
+        created_at: now().toTime().toUnix().int,
+        updated_at: now().toTime().toUnix().int
+      )
+      postList.add(%row)
+    
+    rdb.table("post").insert(postList).await

clients/nim-allographer/example/database/seeder/data/user_seeder.nim

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+import std/json
+import std/strformat
+import std/asyncdispatch
+import std/oids
+import std/times
+import ../../../../src/allographer/query_builder
+import ../../connection
+import ../../schema
+
+proc userSeeder*() {.async.} =
+  seeder(rdb, "user"):
+    var userList: seq[JsonNode]
+    for i in 1..10:
+      let row = UserTable(
+        id: $genOid(),
+        name: &"user {i}",
+        email: &"user{i}@example.com",
+        password: &"password{i}",
+        created_at: now().toTime().toUnix().int,
+        updated_at: now().toTime().toUnix().int,
+      )
+      userList.add(%row)
+
+    rdb.table("user").insert(userList).await

clients/nim-allographer/example/database/seeder/develop.nim

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+import std/asyncdispatch
+import std/os
+import ./data/user_seeder
+import ./data/post_seeder
+
+
+proc seed() {.async.} =
+  let env = getEnv("APP_ENV")
+  if env != "develop":
+    raise newException(CatchableError, "This command is only available in the develop environment")
+
+  userSeeder().await
+  postSeeder().await
+
+
+seed().waitFor()

clients/nim-allographer/example/database/seeder/production.nim

@@ -0,0 +1,14 @@
+import std/asyncdispatch
+import std/os
+import ./data/user_seeder
+import ./data/post_seeder
+
+proc seed() =
+  let env = getEnv("APP_ENV")
+  if env != "production":
+    raise newException(Exception, "This command is only available in the production environment")
+
+  userSeeder().waitFor()
+  postSeeder().waitFor()
+
+seed()

clients/nim-allographer/example/database/seeder/staging.nim

@@ -0,0 +1,14 @@
+import std/asyncdispatch
+import std/os
+import ./data/user_seeder
+import ./data/post_seeder
+
+proc seed() =
+  let env = getEnv("APP_ENV")
+  if env != "staging":
+    raise newException(Exception, "This command is only available in the staging environment")
+
+  userSeeder().waitFor()
+  postSeeder().waitFor()
+
+seed()