Add Fan Suction sensor (reg 52) and flag reg 45 as disputed

[stuartj1-1981]

Summary

This PR adds support for a new sensor (register 52 "Fan Suction") and documents a naming dispute for register 45 that requires further investigation before resolution.

Key Changes

• New Sensor: Added register 52 "Fan Suction" with Pa unit based on HP installer page label (PR Update registers based on cross-check with installer page #23, thanks @johncuthbertuk)

  • Scale: 1, Unit: Pa, Icon: mdi:fan, Class: pressure
  • Display precision set to 0 for cleaner output
  • Includes detailed comments about unit verification needs and typical axial fan behavior

• Disputed Register: Flagged register 45 with detailed dispute documentation

  • Decoder currently names it "DHW Cylinder Temp"
  • identified.md documents it as "Discharge Gas Temp"
  • Added investigation notes: 2026-02-18 DHW cycle data shows 52.4→54.4°C behavior consistent with cylinder probe
  • Resolution requires cross-plotting regs 45/56/19 over the DHW window to determine correct identity

• Held Changes: Documented two changes from PR Update registers based on cross-check with installer page #23 that are intentionally held pending resolution:

  • Register 50 rename ("Reported COP" → "Suction") conflicts with reg 24 "Suction Pressure"
  • Requires defrost or saturation cross-check to settle

• Version Bump: Updated to 4.10.0

Implementation Details

The Fan Suction sensor includes cautionary comments about unit verification since:

• No observed range has been logged yet
• If raw values are 0-100, percentage may be more appropriate
• Monobloc axial fans typically see ~0 Pa external static pressure

The register 45 dispute is thoroughly documented with specific test methodology (plot over 2026-02-18 06:30-08:21 DHW window) to enable future resolution in a single commit.

https://claude.ai/code/session_01UzEvwbJCZWxatMhVohBiyf