[Device support] OPPO CPH2603

Thanks for helping add support for your device. The details below were collected on-device.

### Device

```
Amply device-support request
report_schema=10
app_version=0.5.0-beta0 (500000)
distribution=foss/beta
manufacturer=OPPO
brand=OPPO
model=CPH2603
device=OP5A0BL1
product=CPH2603
fingerprint=OPPO/CPH2603/OP5A0BL1:16/BP2A.250605.015/U.R4T2.574a15c-32fa661:user/release-keys
android_sdk=36
android_release=16
is_phone=true
has_charging_optimization=false
one_ui_version=none
hyperos_version=none
oplus_rom_version=16
is_lineageos=false
lineageos_version=none
is_grapheneos=false
lineage_cc_provider=unknown
lineage_cc_mode=unknown
lineage_cc_limit_mechanism=UNKNOWN
probe_protect_battery=absent
probe_battery_charge_limit=absent
probe_regular_charge_protection=present
probe_smart_charge_protection=present
has_lineage_settings_provider=false
adapter=oneplus-lab
adapter_matched=true
adapter_control_enabled=false
contribution_wanted=true
battery_charging_status=0
battery_plugged=true
```

### What is the manufacturer's battery-protection feature called on this device? (optional)

Start by reading the existing device-support handling for the oneplus-lab adapter and comparing similar device reports. Confirm the manufacturer's battery-protection feature name on the OPPO CPH2603, then determine what support behavior should be verified and whether the repository has relevant tests.

Written by the indexing model from the issue text.