feat(net_connect): add net_connect component for unified network connectivity

Port the network connection functionality from esp-idf's
protocol_examples_common component to esp-protocols as a standalone
net_connect component.

Changes:
- Port all network connection code from esp-idf/examples/common_components/protocol_examples_common
- Rename functions from example_* prefix to net_* prefix for consistency
- Add unified API supporting WiFi, Ethernet, Thread, and PPP interfaces
- Add comprehensive Kconfig options for all connection types
- Add net_connect_example demonstrating component usage
- Update component structure with proper CMakeLists.txt and idf_component.yml
- Add README with usage instructions for all supported interfaces

The component provides a unified interface for establishing network
connectivity across multiple transport types, simplifying network setup
in protocol examples and applications.

Supported interfaces:
- WiFi (Station mode with configurable scan methods)
- Ethernet (EMAC and SPI-based)
- Thread (IEEE802.15.4 native or RCP)
- PPP (Point-to-Point Protocol over Serial/USB)

All configuration is done via Kconfig menuconfig, making it easy to
enable/disable specific interfaces and configure connection parameters.

Author: abhik-roy85

.pre-commit-config.yaml

@@ -57,8 +57,8 @@ repos:
   - repo: local
     hooks:
       - id: commit message scopes
-        name: "commit message must be scoped with: mdns, dns, modem, websocket, asio, mqtt_cxx, console, common, eppp, tls_cxx, mosq, sockutls, lws, modem_sim"
-        entry: '\A(?!(feat|fix|ci|bump|test|docs|chore)\((mdns|dns|modem|common|console|websocket|asio|mqtt_cxx|examples|eppp|tls_cxx|mosq|sockutls|lws|modem_sim)\)\:)'
+        name: "commit message must be scoped with: mdns, dns, modem, websocket, asio, mqtt_cxx, console, common, eppp, tls_cxx, mosq, sockutls, lws, modem_sim, net_connect"
+        entry: '\A(?!(feat|fix|ci|bump|test|docs|chore)\((mdns|dns|modem|common|console|websocket|asio|mqtt_cxx|examples|eppp|tls_cxx|mosq|sockutls|lws|modem_sim|net_connect)\)\:)'
         language: pygrep
         args: [--multiline]
         stages: [commit-msg]

components/net_connect/CMakeLists.txt

@@ -0,0 +1,52 @@
+idf_build_get_property(target IDF_TARGET)
+
+if(${target} STREQUAL "linux")
+    # Header only library for linux
+
+    idf_component_register(INCLUDE_DIRS include
+                           SRCS protocol_examples_utils.c)
+    return()
+endif()
+
+set(srcs "stdin_out.c"
+         "addr_from_stdin.c"
+         "connect.c"
+         "wifi_connect.c"
+         "protocol_examples_utils.c")
+
+if(CONFIG_NET_CONNECT_PROVIDE_WIFI_CONSOLE_CMD)
+    list(APPEND srcs "console_cmd.c")
+endif()
+
+if(CONFIG_NET_CONNECT_CONNECT_ETHERNET)
+    list(APPEND srcs "eth_connect.c")
+endif()
+
+if(CONFIG_NET_CONNECT_CONNECT_THREAD)
+    list(APPEND srcs "thread_connect.c")
+endif()
+
+if(CONFIG_NET_CONNECT_CONNECT_PPP)
+    list(APPEND srcs "ppp_connect.c")
+endif()
+
+
+idf_component_register(SRCS "${srcs}"
+                       INCLUDE_DIRS "include"
+                       PRIV_REQUIRES esp_netif esp_driver_gpio esp_driver_uart esp_wifi vfs console esp_eth openthread)
+
+if(CONFIG_NET_CONNECT_PROVIDE_WIFI_CONSOLE_CMD)
+    idf_component_optional_requires(PRIVATE console)
+endif()
+
+if(CONFIG_NET_CONNECT_CONNECT_ETHERNET)
+    idf_component_optional_requires(PUBLIC esp_eth)
+endif()
+
+if(CONFIG_NET_CONNECT_CONNECT_THREAD)
+    idf_component_optional_requires(PRIVATE openthread)
+endif()
+
+if(CONFIG_NET_CONNECT_CONNECT_PPP)
+    idf_component_optional_requires(PRIVATE esp_tinyusb espressif__esp_tinyusb)
+endif()