docs(core): add and modify docs to context and cache

[no changelog]

core/src/storage/cache_codec.py

@@ -16,6 +16,11 @@ SESSION_ID_LENGTH = const(32)
 
 
 class SessionCache(DataCache):
+    """
+    A cache for storing values that depend on seed derivation
+    or are specific to a `protocol_v1` session.
+    """
+
     def __init__(self) -> None:
         self.session_id = bytearray(SESSION_ID_LENGTH)
         if utils.BITCOIN_ONLY:

core/src/storage/cache_common.py

@@ -36,6 +36,11 @@ class InvalidSessionError(Exception):
 
 
 class DataCache:
+    """
+    A single unit of cache storage, designed to store common-type
+    values efficiently in bytearrays in a sequential manner.
+    """
+
     fields: Sequence[int]  # field sizes
 
     def __init__(self) -> None:
@@ -110,6 +115,11 @@ class DataCache:
 
 
 class SessionlessCache(DataCache):
+    """
+    A cache for values that are independent of both
+    passphrase seed derivation and the active session.
+    """
+
     def __init__(self) -> None:
         self.fields = (
             64,  # APP_COMMON_SEED_WITHOUT_PASSPHRASE

core/src/trezor/wire/codec/codec_context.py

@@ -16,11 +16,7 @@ if TYPE_CHECKING:
 
 
 class CodecContext(Context):
-    """Wire context.
-
-    Represents USB communication inside a particular session on a particular interface
-    (i.e., wire, debug, single BT connection, etc.)
-    """
+    """ "Wire context" for `protocol_v1`."""
 
     def __init__(
         self,

core/src/trezor/wire/message_handler.py

@@ -53,7 +53,7 @@ WIRE_BUFFER = bytearray(_PROTOBUF_BUFFER_SIZE)
 
 
 async def handle_single_message(ctx: Context, msg: Message) -> bool:
-    """Handle a message that was loaded from USB by the caller.
+    """Handle a message that was loaded from a WireInterface by the caller.
 
     Find the appropriate handler, run it and write its result on the wire. In case
     a problem is encountered at any point, write the appropriate error on the wire.

core/src/trezor/wire/protocol_common.py

@@ -24,6 +24,13 @@ class Message:
 
 
 class Context:
+    """Wire context.
+
+    Represents communication between the Trezor device and a host within
+    a specific session over a particular interface (i.e., wire, debug,
+    single Bluetooth connection, etc.).
+    """
+
     channel_id: bytes
 
     def __init__(self, iface: WireInterface, channel_id: bytes | None = None) -> None: