Remove outdated GPU marketplace endpoint and fix staking service logic

- Remove duplicate `/marketplace/gpu/{gpu_id}` endpoint from marketplace_gpu.py
- Remove marketplace_gpu router inclusion from main.py (already included elsewhere)
- Fix staking service staker_count logic to check existing stakes before increment/decrement
- Add minimum stake amount validation (100 AITBC)
- Add proper error handling for stake not found cases
- Fix staking pool update to commit and refresh after modifications
- Update CLI send_transaction to use chain

dev/validator_keys.json

@@ -1,8 +1,8 @@
 {
   "0x1234567890123456789012345678901234567890": {
-    "private_key_pem": "-----BEGIN PRIVATE KEY-----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\n6gRYmkAIONs8mgx4iqNWsLE=\n-----END PRIVATE KEY-----\n",
-    "public_key_pem": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzg+uL8lmIDn/CEk9J6i7\n9iR3YklHLtAYh829MYzJtMKdG5G2GqlykSo76bD7DMg00WvNI/dRDMwhDUb8BJgb\n8jKoQAbyG9wLu6VUcfpYrr7A+3Zn/WfJEbfroN5n3YaBGfDlxDUqEJ4NCXMMvJ5B\nsj8WtZ73bmbDUElM3hHwY7Ar158WLqdwHMMCFgEAWhWCUilPYHGSeCmcugFj2VFH\neOFHQeZdys/XZVgtTAhr2NO2zJ9JQz9a1S3TXznIPQsbFnbDuscRncGryabJzx6Y\npgbY5tyYCEOQMz4u8elVBqOox6Mi6at9m12no6Go61H8CZAQxa24SMUvyJ0Q8GyT\nhQIDAQAB\n-----END PUBLIC KEY-----\n",
-    "created_at": 1776096709.9975224,
-    "last_rotated": 1776096709.997713
+    "private_key_pem": "-----BEGIN PRIVATE KEY-----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\nakhZt0S6Rf0IVxot+q+oOg==\n-----END PRIVATE KEY-----\n",
+    "public_key_pem": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnNFX0ZiynJVpDWDuTQn+\nzE+LLPCTJESjJqcFIRDfwZw8ghsYAKPqaPPCgh6By5uSYliAy0wC50JIEF1y/A6Q\nml8DLQSAs26v83w8nuy9dePpXJtwl0kYZhC5i1fs6NvT4heVDVedpuGX1dztaKYR\nQ0NF5xhaKNXhtXn5c3TGAjkqMY61f2dJbZaHNz/jtcEl3LbTcOA0PX6p6Q0U42Vi\nslUs9nSOr5ZzmybM357cpM1pidmFNU7RXYfNdElNy09X1e9onG1ptSoxeTu09vvl\npfiSddw/HCAYsFa7lrgjJ6PA+WHygt+bkUvDm+MJjA0BJ0AwAhCl5keAeXkOEhLW\nfQIDAQAB\n-----END PUBLIC KEY-----\n",
+    "created_at": 1776106994.919443,
+    "last_rotated": 1776106994.9196188
   }
 }