feat(net_connect): introduce unified network connectivity component

Key features:
- Port network connection logic from protocol_examples_common into a standalone net_connect component.
- Provide unified APIs for WiFi, Ethernet, Thread, and PPP connectivity.
- Add comprehensive Kconfig options and example usage.
- Introduce programmatic WiFi STA configuration APIs:
  - net_configure_wifi_sta()
  - net_connect_wifi()
  - net_disconnect_wifi()
- Simplify WiFi connection flow and remove redundant config prefixes.
- Add backward-compatibility mappings via sdkconfig.rename.

Ethernet migration & cleanup:
- Migrate Ethernet setup to the new ethernet_init component.
- Simplify Kconfig by delegating Ethernet options to the main config.
- Add interface init/deinit logging.
- Fix missing Thread/PPP shutdown handlers.
- Remove obsolete net_get_eth_handle() API.

Misc:
- Update component structure, CMake files, and general cleanup.

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(${target} STREQUAL "linux")
+    # Header only library for linux
+
+    idf_component_register(INCLUDE_DIRS include
+                           SRCS protocol_examples_utils.c)
+    return()
+endif()
+
+set(srcs "stdin_out.c"
+         "addr_from_stdin.c"
+         "connect.c"
+         "wifi_connect.c"
+         "protocol_examples_utils.c")
+
+if(CONFIG_NET_CONNECT_PROVIDE_WIFI_CONSOLE_CMD)
+    list(APPEND srcs "console_cmd.c")
+endif()
+
+if(CONFIG_NET_CONNECT_ETHERNET)
+    list(APPEND srcs "eth_connect.c")
+endif()
+
+if(CONFIG_NET_CONNECT_THREAD)
+    list(APPEND srcs "thread_connect.c")
+endif()
+
+if(CONFIG_NET_CONNECT_PPP)
+    list(APPEND srcs "ppp_connect.c")
+endif()
+
+
+idf_component_register(SRCS "${srcs}"
+                       INCLUDE_DIRS "include"
+                       PRIV_REQUIRES esp_netif esp_driver_gpio esp_driver_uart esp_wifi vfs console openthread)
+
+if(CONFIG_NET_CONNECT_PROVIDE_WIFI_CONSOLE_CMD)
+    idf_component_optional_requires(PRIVATE console)
+endif()
+
+if(CONFIG_NET_CONNECT_ETHERNET)
+    idf_component_optional_requires(PRIVATE esp_eth)
+endif()
+
+if(CONFIG_NET_CONNECT_THREAD)
+    idf_component_optional_requires(PRIVATE openthread)
+endif()
+
+if(CONFIG_NET_CONNECT_PPP)
+    idf_component_optional_requires(PRIVATE esp_tinyusb espressif__esp_tinyusb)
+endif()

components/net_connect/Kconfig.projbuild

@@ -0,0 +1,316 @@
+menu "Net Connect Configuration"
+
+    orsource "$IDF_PATH/examples/common_components/env_caps/$IDF_TARGET/Kconfig.env_caps"
+
+    config NET_CONNECT_WIFI
+        bool "connect using WiFi interface"
+        depends on !IDF_TARGET_LINUX && (SOC_WIFI_SUPPORTED || ESP_WIFI_REMOTE_ENABLED || ESP_HOST_WIFI_ENABLED)
+        default y if SOC_WIFI_SUPPORTED
+        help
+            Protocol examples can use Wi-Fi, Ethernet and/or Thread to connect to the network.
+            Choose this option to connect with WiFi
+
+    if NET_CONNECT_WIFI
+        config NET_CONNECT_WIFI_SSID_PWD_FROM_STDIN
+            bool "Get ssid and password from stdin"
+            default n
+            help
+                Give the WiFi SSID and password from stdin.
+
+        config NET_CONNECT_PROVIDE_WIFI_CONSOLE_CMD
+            depends on !NET_CONNECT_WIFI_SSID_PWD_FROM_STDIN
+            bool "Provide wifi connect commands"
+            default y
+            help
+                Provide wifi connect commands for esp_console.
+                Please use `example_register_wifi_connect_commands` to register them.
+
+        config NET_CONNECT_WIFI_SSID
+            depends on !NET_CONNECT_WIFI_SSID_PWD_FROM_STDIN
+            string "WiFi SSID"
+            default "myssid"
+            help
+                SSID (network name) for the example to connect to.
+
+        config NET_CONNECT_WIFI_PASSWORD
+            depends on !NET_CONNECT_WIFI_SSID_PWD_FROM_STDIN
+            string "WiFi Password"
+            default "mypassword"
+            help
+                WiFi password (WPA or WPA2) for the example to use.
+                Can be left blank if the network has no security set.
+
+        config NET_CONNECT_WIFI_CONN_MAX_RETRY
+            int "Maximum retry"
+            default 6
+            help
+                Set the Maximum retry to avoid station reconnecting to the AP unlimited,
+                in case the AP is really inexistent.
+
+        choice NET_CONNECT_WIFI_SCAN_METHOD
+            prompt "WiFi Scan Method"
+            default NET_CONNECT_WIFI_SCAN_METHOD_ALL_CHANNEL
+            help
+                WiFi scan method:
+
+                If "Fast" is selected, scan will end after find SSID match AP.
+
+                If "All Channel" is selected, scan will end after scan all the channel.
+
+            config NET_CONNECT_WIFI_SCAN_METHOD_FAST
+                bool "Fast"
+            config NET_CONNECT_WIFI_SCAN_METHOD_ALL_CHANNEL
+                bool "All Channel"
+        endchoice
+
+        menu "WiFi Scan threshold"
+            config NET_CONNECT_WIFI_SCAN_RSSI_THRESHOLD
+                int "WiFi minimum rssi"
+                range -127 0
+
+                default -127
+                help
+                    The minimum rssi to accept in the scan mode.
+
+            choice NET_CONNECT_WIFI_SCAN_AUTH_MODE_THRESHOLD
+                prompt "WiFi Scan auth mode threshold"
+                default NET_CONNECT_WIFI_AUTH_OPEN
+                help
+                    The weakest authmode to accept in the scan mode.
+
+                config NET_CONNECT_WIFI_AUTH_OPEN
+                    bool "OPEN"
+                config NET_CONNECT_WIFI_AUTH_WEP
+                    bool "WEP"
+                config NET_CONNECT_WIFI_AUTH_WPA_PSK
+                    bool "WPA PSK"
+                config NET_CONNECT_WIFI_AUTH_WPA2_PSK
+                    bool "WPA2 PSK"
+                config NET_CONNECT_WIFI_AUTH_WPA_WPA2_PSK
+                    bool "WPA WPA2 PSK"
+                config NET_CONNECT_WIFI_AUTH_WPA2_ENTERPRISE
+                    bool "WPA2 ENTERPRISE"
+                config NET_CONNECT_WIFI_AUTH_WPA3_PSK
+                    bool "WPA3 PSK"
+                config NET_CONNECT_WIFI_AUTH_WPA2_WPA3_PSK
+                    bool "WPA2 WPA3 PSK"
+                config NET_CONNECT_WIFI_AUTH_WAPI_PSK
+                    bool "WAPI PSK"
+            endchoice
+        endmenu
+
+        choice NET_CONNECT_WIFI_CONNECT_AP_SORT_METHOD
+            prompt "WiFi Connect AP Sort Method"
+            default NET_CONNECT_WIFI_CONNECT_AP_BY_SIGNAL
+            help
+                WiFi connect AP sort method:
+
+                If "Signal" is selected, Sort matched APs in scan list by RSSI.
+
+                If "Security" is selected, Sort matched APs in scan list by security mode.
+
+            config NET_CONNECT_WIFI_CONNECT_AP_BY_SIGNAL
+                bool "Signal"
+            config NET_CONNECT_WIFI_CONNECT_AP_BY_SECURITY
+                bool "Security"
+        endchoice
+    endif
+
+    config NET_CONNECT_ETHERNET
+        bool "connect using Ethernet interface"
+        depends on !IDF_TARGET_LINUX
+        default y if !NET_CONNECT_WIFI && !NET_CONNECT_THREAD
+        help
+            Protocol examples can use Wi-Fi, Ethernet and/or Thread to connect to the network.
+            Choose this option to enable connection with Ethernet.
+            Go to `Top -> Ethernet Configuration` to configure the Ethernet interface.
+
+    config NET_CONNECT_DISABLE_ETHERNET_CONFIG
+        bool
+        select ETHERNET_INIT_OVERRIDE_DISABLE
+        default y if !NET_CONNECT_ETHERNET
+
+    config NET_CONNECT_PPP
+        bool "connect using Point to Point interface"
+        select LWIP_PPP_SUPPORT
+        help
+            Protocol examples can use PPP connection over serial line.
+            Choose this option to connect to the ppp server running
+            on your laptop over a serial line (either UART or USB ACM)
+
+    if NET_CONNECT_PPP
+        choice NET_CONNECT_PPP_DEVICE
+            prompt "Choose PPP device"
+            default NET_CONNECT_PPP_DEVICE_USB
+            help
+                Select which peripheral to use to connect to the PPP server.
+
+            config NET_CONNECT_PPP_DEVICE_USB
+                bool "USB"
+                depends on SOC_USB_OTG_SUPPORTED
+                select TINYUSB_CDC_ENABLED
+                help
+                    Use USB ACM device.
+
+            config NET_CONNECT_PPP_DEVICE_UART
+                bool "UART"
+                help
+                    Use UART.
+
+        endchoice
+
+        menu "UART Configuration"
+            depends on NET_CONNECT_PPP_DEVICE_UART
+            config NET_CONNECT_UART_TX_PIN
+                int "TXD Pin Number"
+                default 4
+                range 0 31
+                help
+                    Pin number of UART TX.
+
+            config NET_CONNECT_UART_RX_PIN
+                int "RXD Pin Number"
+                default 5
+                range 0 31
+                help
+                    Pin number of UART RX.
+
+            config NET_CONNECT_UART_BAUDRATE
+                int "UART Baudrate"
+                default 115200
+                range 9600 3000000
+                help
+                    Baudrate of the UART device
+
+        endmenu
+
+        config NET_CONNECT_PPP_CONN_MAX_RETRY
+            int "Maximum retry"
+            default 6
+            help
+                Set the Maximum retry to avoid station reconnecting if the pppd
+                is not available
+
+    endif # NET_CONNECT_PPP
+
+    config NET_CONNECT_THREAD
+        bool "Connect using Thread interface"
+        depends on !IDF_TARGET_LINUX && OPENTHREAD_ENABLED
+        default y if SOC_IEEE802154_SUPPORTED
+        select NET_CONNECT_IPV6
+        help
+            Protocol examples can use Wi-Fi, Ethernet and/or Thread to connect to the network.
+            Choose this option to connect with Thread.
+            The operational active dataset of the Thread network can be configured in openthread
+            component at '->Components->OpenThread->Thread Core Features->Thread Operational Dataset'
+
+    if NET_CONNECT_THREAD
+        config NET_CONNECT_THREAD_TASK_STACK_SIZE
+            int "Example Thread task stack size"
+            default 8192
+            help
+                Thread task stack size
+
+        menu "Radio Spinel Options"
+            depends on OPENTHREAD_RADIO_SPINEL_UART || OPENTHREAD_RADIO_SPINEL_SPI
+
+            config NET_CONNECT_THREAD_UART_RX_PIN
+                depends on OPENTHREAD_RADIO_SPINEL_UART
+                int "Uart Rx Pin"
+                default 17
+
+            config NET_CONNECT_THREAD_UART_TX_PIN
+                depends on OPENTHREAD_RADIO_SPINEL_UART
+                int "Uart Tx pin"
+                default 18
+
+            config NET_CONNECT_THREAD_UART_BAUD
+                depends on OPENTHREAD_RADIO_SPINEL_UART
+                int "Uart baud rate"
+                default 460800
+
+            config NET_CONNECT_THREAD_UART_PORT
+                depends on OPENTHREAD_RADIO_SPINEL_UART
+                int "Uart port"
+                default 1
+
+            config NET_CONNECT_THREAD_SPI_CS_PIN
+                depends on OPENTHREAD_RADIO_SPINEL_SPI
+                int "SPI CS Pin"
+                default 10
+
+            config NET_CONNECT_THREAD_SPI_SCLK_PIN
+                depends on OPENTHREAD_RADIO_SPINEL_SPI
+                int "SPI SCLK Pin"
+                default 12
+
+            config NET_CONNECT_THREAD_SPI_MISO_PIN
+                depends on OPENTHREAD_RADIO_SPINEL_SPI
+                int "SPI MISO Pin"
+                default 13
+
+            config NET_CONNECT_THREAD_SPI_MOSI_PIN
+                depends on OPENTHREAD_RADIO_SPINEL_SPI
+                int "SPI MOSI Pin"
+                default 11
+
+            config NET_CONNECT_THREAD_SPI_INTR_PIN
+                depends on OPENTHREAD_RADIO_SPINEL_SPI
+                int "SPI Interrupt Pin"
+                default 8
+        endmenu
+
+    endif
+
+    config NET_CONNECT_IPV4
+        bool
+        depends on LWIP_IPV4
+        default n if NET_CONNECT_THREAD
+        default y
+
+    config NET_CONNECT_IPV6
+        depends on NET_CONNECT_WIFI || NET_CONNECT_ETHERNET || NET_CONNECT_PPP || NET_CONNECT_THREAD
+        bool "Obtain IPv6 address"
+        default y
+        select LWIP_IPV6
+        select LWIP_PPP_ENABLE_IPV6 if NET_CONNECT_PPP
+        help
+            By default, examples will wait until IPv4 and IPv6 local link addresses are obtained.
+            Disable this option if the network does not support IPv6.
+            Choose the preferred IPv6 address type if the connection code should wait until other than
+            the local link address gets assigned.
+            Consider enabling IPv6 stateless address autoconfiguration (SLAAC) in the LWIP component.
+
+    if NET_CONNECT_IPV6
+        choice NET_CONNECT_PREFERRED_IPV6
+            prompt "Preferred IPv6 Type"
+            default NET_CONNECT_IPV6_PREF_LOCAL_LINK
+            help
+                Select which kind of IPv6 address the connect logic waits for.
+
+            config NET_CONNECT_IPV6_PREF_LOCAL_LINK
+                bool "Local Link Address"
+                help
+                    Blocks until Local link address assigned.
+
+            config NET_CONNECT_IPV6_PREF_GLOBAL
+                bool "Global Address"
+                help
+                    Blocks until Global address assigned.
+
+            config NET_CONNECT_IPV6_PREF_SITE_LOCAL
+                bool "Site Local Address"
+                help
+                    Blocks until Site link address assigned.
+
+            config NET_CONNECT_IPV6_PREF_UNIQUE_LOCAL
+                bool "Unique Local Link Address"
+                help
+                    Blocks until Unique local address assigned.
+
+        endchoice
+
+    endif
+
+
+endmenu