feat: add field comments, local time zone decoding and in-value cancellation

Assisted-by: GLM 5.3 Flash

docs/API.md

@@ -314,6 +314,12 @@ error. The date-time types take a bare timestamp and never a quoted string, so a
 document that writes a date-time with quotes does not decode into them, and
 neither `encoding.TextUnmarshaler` nor the embedded `time.Time` changes that.
 
+`NewDecoder().LocalTimeLocation(loc)` lets a local date-time fill a plain
+`time.Time` destination as well: the wall-clock value is carried in the
+location given, relabelled rather than shifted, so `07:32` in the document is
+`07:32` in the zone. Without the option the wrapper types are the only
+destinations a local kind fills.
+
 ### Arrays of tables
 
 A `[[a]]` block parses into a `[]map[string]any` element of the tree. When the
@@ -438,7 +444,9 @@ one, so it does not depend on map iteration order.
 `ParseContext`, `UnmarshalContext` and `(*Decoder).DecodeContext` accept a
 `context.Context`. An already-cancelled context short-circuits with
 `context.Canceled` before any work begins; afterwards the context is checked
-every 64 top-level statements.
+every 64 top-level statements, and inside a value too: an array, an inline
+table and a multi-line string check every 64 elements or lines, so one huge
+value cannot hold the parse past its cancellation.
 
 ### Flow
 
@@ -509,6 +517,11 @@ its key whether the table it came from was written inline or under a header.
   embedded struct tagged this way does the same. A field holding an array of
   tables is an error under `inline`, because the inline form would re-parse
   as a value array and change the value's Go type.
+- `comment=text` carries a comment for the field, which
+  `NewEncoder().EmitFieldComments()` prints above the field's line or
+  header, each line of a multi-line text with its own `# ` marker. Go doc
+  comments are not visible to reflection, so the tag is the channel that
+  carries the text; without the encoder option the tag is ignored.
 
 ```go
 type Config struct {
@@ -817,6 +830,7 @@ encoder:
 | `OmitEmptyArrays()` | off | skip `key = []` for empty scalar arrays |
 | `UseLiteralMultiline(threshold int)` | `0` | emit multi-line strings of at least `threshold` bytes as literal `'''...'''` |
 | `InlineTables(threshold int)` | `0` | write a sub-table inline when its single-line form is at most `threshold` bytes |
+| `EmitFieldComments()` | off | print the `comment=` tag option of a field above its line or header |
 
 ```go
 out, err := interpres.NewEncoder().