Context-aware strapping pin warnings based on pin direction

[FredM67]

Describe the enhancement

Problem

Currently, ESPHome shows strapping pin warnings for all uses of strapping pins, regardless of whether the pin is configured as input or output. This leads to unnecessary warnings in cases where there's actually no risk.

Background

ESP32 strapping pins are sampled during boot to configure chip behavior (boot mode, flash voltage, JTAG, etc.). The key distinction is:

1. Always sensitive pins (e.g., GPIO0): Affect boot mode regardless of later configuration. External circuitry can interfere with boot even if the pin is later used as output.
2. Boot-time input pins (e.g., GPIO12 on ESP32): Only read during boot to set flash voltage. If configured as an output after boot (e.g., switch, relay, LED), there's no issue since the boot decision already happened.

Use cases

Current behavior

switch:
  - platform: gpio
    pin: GPIO12  # Warning shown even though this is an output
    name: "My Relay"

Shows: GPIO12 is a strapping pin and should be avoided...

Visual examples

No response

Anything else?

If accepted, I'm ready to implement this new feature.

[nagyrobi]

The fact that you're using it for output doesn't matter because electronically it's still connected to active peripherals (specifically if it's a relay there must be at least a powered transistor directly connected to the pin; which can actually behave like a pull-up or pull-down from the pin perspective, depending on the resistors around the transistor, or the transistor's internal impedance aswell). So the warning is legit, because it makes you aware of this potential risk.
If you're absolutely sure about what you're doing, just mute the warning with the appropriate ignore configuration option in yaml. Not a big effort at all.

[FredM67]

You're right that external circuitry can affect strapping during boot. However, the severity varies significantly between pins. GPIO0 wrong = won't boot. GPIO12 wrong on modern modules with efuses = usually irrelevant. Perhaps differentiated warning levels (error vs info) based on pin criticality and direction would help users focus on actual risks?