feat(mining): integrate mining subsystem into existing modules

- CMakeLists.txt: add 6 mining sources + tcp_transport dependency
- config.h/c: mining_payout_mode_t enum, mining config fields, JSON parsing
- tollgate_main.c: mining init in start_services(), stratum_client_tick in main loop
- tollgate_api.c: GET /mining/job, POST /mining/share, GET /mining/stats endpoints
- session.h/c: payment_method_t enum (CASHU/MINING/BYTES)
- firewall.h/c: sandbox allowlist for mining port + mint URLs
- tollgate_client.h/c: TG_CLIENT_MINING state, mining discovery tag parsing
- captive_portal.c: tabbed UI with Cashu/Mine tabs, live hashrate polling

1 files changed, 2 insertions, 0 deletions

diff --git a/main/firewall.h b/main/firewall.h
index f177eaa..77300e2 100644
--- a/main/firewall.h
+++ b/main/firewall.h
@@ -11,6 +11,8 @@ struct pbuf;
 #define FW_MAX_MAC_LEN 18
 
 esp_err_t firewall_init(esp_ip4_addr_t ap_ip);
+void firewall_set_mining_port(uint16_t port);
+void firewall_set_sandbox_mint_access(bool enabled);
 void firewall_grant_access(uint32_t client_ip);
 void firewall_revoke_access(uint32_t client_ip);
 void firewall_revoke_all(void);