[valve] Add endstop_valve platform (cover/valve refactor 4/5)

[exciton]

Cover/Valve Actuator Refactor — PR Series

Step	PR	Title	Depends on
1/5	#3	[actuator] Add shared actuator base component	—
2/5	#4	[actuator] Add EndstopActuatorBase, migrate EndstopCover	Step 1 (#3)
3/5	#5	[actuator] Add TimeBasedActuatorBase, migrate TimeBasedCover	Step 1 (#3)
4/5	#6	[valve] Add endstop_valve platform	Step 2 (#4)
5/5	#7	[valve] Add time_based_valve platform	Step 3 (#5)

Merge order: #3 → #4 and #5 (parallel) → #6 and #7 (parallel)

This PR: Step 4/5

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What does this implement/fix?

Adds a new endstop_valve platform for the valve component, providing the same endstop-based position control that endstop cover has, reusing EndstopActuatorBase from step 2/5 with no logic duplication.

New esphome/components/endstop_valve/:

• EndstopValve inherits EndstopActuatorBase + Valve
• Supports open/close endstop binary sensors, open/close/stop triggers, position tracking, and optional max duration
• Full YAML schema mirroring the endstop cover platform
• dump_config() logging

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): fixes

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#

Test Environment

• ESP32
• ESP32 IDF
• ESP8266
• RP2040
• BK72xx
• RTL87xx

Example entry for config.yaml:

valve:
  - platform: endstop_valve
    name: "My Valve"
    open_action:
      - switch.turn_on: open_switch
    close_action:
      - switch.turn_on: close_switch
    stop_action:
      - switch.turn_off: open_switch
    open_endstop: open_binary_sensor
    close_endstop: close_binary_sensor
    open_duration: 25s
    close_duration: 23s

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.

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Generated by Claude Code

[github-actions]

Memory Impact Analysis

Components: endstop
Platform: esp8266-ard

Metric	Target Branch	This PR	Change
RAM	29,064 bytes	29,328 bytes	📈 🔸 +264 bytes (+0.91%)
Flash	272,047 bytes	273,711 bytes	📈 🔸 +1,664 bytes (+0.61%)

📊 Component Memory Breakdown

Component	Target Flash	PR Flash	Change
[esphome]valve	0 bytes	661 bytes	📈 🔸 +661 bytes (0.00%)
[esphome]core	8,070 bytes	8,420 bytes	📈 🚨 +350 bytes (+4.34%)
[esphome]endstop	1,825 bytes	2,172 bytes	📈 🚨 +347 bytes (+19.01%)
[esphome]template	761 bytes	816 bytes	📈 🚨 +55 bytes (+7.23%)
app_framework	1,406 bytes	1,446 bytes	📈 +40 bytes (+2.84%)

🔍 Symbol-Level Changes (click to expand)

Changed Symbols

Symbol	Target Size	PR Size	Change
setup	742 bytes	1,074 bytes	📈 +332 bytes (+44.74%)
esphome::App	152 bytes	172 bytes	📈 +20 bytes (+13.16%)
esphome::COMP_SRC_TABLE	20 bytes	24 bytes	📈 +4 bytes (+20.00%)

New Symbols (top 15)

Symbol	Size
esphome::valve::Valve::publish_state(bool)	283 bytes
esphome::valve::Valve::do_restore_state()	223 bytes
esphome::endstop::EndstopValve::dump_config()	192 bytes
endstop__endstop_valve_test__pstorage	104 bytes
vtable for esphome::endstop::EndstopValve	100 bytes
esphome::template_::TemplateBinarySensor::TemplateBinarySensor()	55 bytes
esphome::valve::ValveRestoreState::apply(esphome::valve::Valve*)	44 bytes
template__bin2__pstorage	44 bytes
vtable for esphome::valve::Valve	44 bytes
setup::{lambda()#2}::_FUN()	40 bytes
esphome::valve::Valve::Valve()	36 bytes
switch__switch__turnonaction_id_5__pstorage	16 bytes
switch__switch__turnonaction_id_4__pstorage	16 bytes
switch__switch__turnonaction_id_6__pstorage	16 bytes
non-virtual thunk to esphome::endstop::EndstopValve::get_traits()	15 bytes
14 more new symbols...	Total: 1,325 bytes

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Note: This analysis measures static RAM and Flash usage only (compile-time allocation).
Dynamic memory (heap) cannot be measured automatically.
⚠️ You must test this PR on a real device to measure free heap and ensure no runtime memory issues.

This analysis runs automatically when components change. Memory usage is measured from a representative test configuration.