[core] Derive CORE state from cached config dict, drop apply_to_core

`StorageJSON.apply_to_core` was the inverse of `from_esphome_core`:
two enumerations of the same fields that had to stay in sync. When a
new CORE attribute joined the validation pipeline, both lists needed
an update.

Replace it with `_populate_core_from_validated_config(config)` in
`compiled_config.py` that reads the cached config dict directly --
same source `read_config` writes into during validation, no separate
sidecar schema. The fast path no longer touches StorageJSON at all;
the sidecar stays in place for the dashboard's existing use.

Drift surface shrinks to: name/friendly_name/build_path under the
esphome block (config schema is stable) + target_platform discovered
via `_is_target_platform` (the canonical detector) + framework via
the `<platform>.framework.type` convention every platform component
already follows.

tests/unit_tests/test_compiled_config.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-import json
 import os
 from pathlib import Path
 from unittest.mock import patch
@@ -25,8 +24,11 @@ _VALIDATED_CONFIG_YAML = """\
 esphome:
   name: lite_test
   friendly_name: Lite Test Device
+  build_path: build/lite_test
 esp32:
   board: nodemcu-32s
+  framework:
+    type: arduino
 logger:
   baud_rate: 115200
 api:
@@ -43,30 +45,6 @@ wifi:
 """
 
 
-def _write_storage(storage_path: Path) -> None:
-    """Write a vanilla StorageJSON sidecar for the cache tests."""
-    storage_path.parent.mkdir(parents=True, exist_ok=True)
-    data = {
-        "storage_version": 1,
-        "name": "lite_test",
-        "friendly_name": "Lite Test Device",
-        "comment": None,
-        "esphome_version": "2026.1.0",
-        "src_version": 1,
-        "address": "192.168.1.42",
-        "web_port": None,
-        "esp_platform": "ESP32",
-        "build_path": "/build/lite_test",
-        "firmware_bin_path": "/build/lite_test/firmware.bin",
-        "loaded_integrations": ["api", "logger", "ota", "wifi"],
-        "loaded_platforms": [],
-        "no_mdns": False,
-        "framework": "arduino",
-        "core_platform": "esp32",
-    }
-    storage_path.write_text(json.dumps(data))
-
-
 def _write_cache(cache_path: Path, body: str = _VALIDATED_CONFIG_YAML) -> Path:
     """Write the cache file and return it."""
     cache_path.parent.mkdir(parents=True, exist_ok=True)
@@ -85,14 +63,14 @@ def _set_cache_mtime(cache_path: Path, yaml_path: Path, *, offset: int) -> None:
 
 @pytest.fixture
 def fresh_cache_files(tmp_path: Path) -> Path:
-    """YAML + StorageJSON + cache, all consistent and fresh."""
+    """YAML + cache, both consistent and fresh."""
     yaml_path = tmp_path / "lite_test.yaml"
     yaml_path.write_text("esphome:\n  name: lite_test\n")
     CORE.config_path = yaml_path
 
-    storage_dir = tmp_path / ".esphome" / "storage"
-    _write_storage(storage_dir / "lite_test.yaml.json")
-    cache = _write_cache(storage_dir / "lite_test.yaml.validated.yaml")
+    cache = _write_cache(
+        tmp_path / ".esphome" / "storage" / "lite_test.yaml.validated.yaml"
+    )
     _set_cache_mtime(cache, yaml_path, offset=5)
 
     return yaml_path
@@ -106,7 +84,7 @@ def test_compiled_config_path_lives_alongside_sidecar(setup_core: Path) -> None:
 
 
 def test_load_compiled_config_happy_path(fresh_cache_files: Path) -> None:
-    """Fresh cache + sidecar → returns config and populates CORE."""
+    """Fresh cache → returns the config and populates CORE from it."""
     config = load_compiled_config(fresh_cache_files)
 
     assert config is not None
@@ -114,40 +92,37 @@ def test_load_compiled_config_happy_path(fresh_cache_files: Path) -> None:
     assert config[CONF_API]["encryption"]["key"] == "6dGhpcyBpcyBhIHRlc3Q="
     assert config["ota"][0]["password"] == "secret"
 
-    # apply_to_core ran as part of the orchestration.
+    # CORE state derives from the cached config dict -- same source
+    # `read_config` uses, no separate sidecar schema.
     assert CORE.name == "lite_test"
-    assert CORE.build_path == Path("/build/lite_test")
+    assert CORE.friendly_name == "Lite Test Device"
+    assert CORE.build_path == CORE.data_dir / "build/lite_test"
     assert CORE.data[KEY_CORE][KEY_TARGET_PLATFORM] == "esp32"
     assert CORE.data[KEY_CORE][KEY_TARGET_FRAMEWORK] == "arduino"
-    assert "api" in CORE.loaded_integrations
 
 
 @pytest.mark.parametrize(
     "scenario",
-    ["missing_cache", "stale_cache", "corrupt_cache", "missing_sidecar"],
+    ["missing_cache", "stale_cache", "corrupt_cache", "missing_esphome_block"],
 )
 def test_load_compiled_config_falls_back(tmp_path: Path, scenario: str) -> None:
     """All non-happy cases return None so the caller falls back."""
     yaml_path = tmp_path / "lite_test.yaml"
     yaml_path.write_text("esphome:\n  name: lite_test\n")
     CORE.config_path = yaml_path
-    storage_dir = tmp_path / ".esphome" / "storage"
-    cache_path = storage_dir / "lite_test.yaml.validated.yaml"
-    sidecar_path = storage_dir / "lite_test.yaml.json"
+    cache_path = tmp_path / ".esphome" / "storage" / "lite_test.yaml.validated.yaml"
 
     if scenario == "missing_cache":
-        pass  # no cache, no sidecar
+        pass  # no cache
     elif scenario == "stale_cache":
-        _write_storage(sidecar_path)
         _set_cache_mtime(_write_cache(cache_path), yaml_path, offset=-60)
     elif scenario == "corrupt_cache":
-        _write_storage(sidecar_path)
         _set_cache_mtime(
             _write_cache(cache_path, "not: valid: yaml: ["), yaml_path, offset=5
         )
-    elif scenario == "missing_sidecar":
-        # Cache fresh + parseable, but no StorageJSON → can't populate CORE.
-        _set_cache_mtime(_write_cache(cache_path), yaml_path, offset=5)
+    elif scenario == "missing_esphome_block":
+        # Parseable YAML but no esphome: block -- can't populate CORE.
+        _set_cache_mtime(_write_cache(cache_path, "logger:\n"), yaml_path, offset=5)
 
     assert load_compiled_config(yaml_path) is None