Add Dumas JSON utility batch

README.md

@@ -24,6 +24,21 @@
   - Output: updated `JSON`
   - Writes a parsed JSON value into a nested path without mutating the original object.
 
+- `Dumas JSON Has Key`
+  - Inputs: `json_object`, `path`
+  - Output: `BOOLEAN`
+  - Checks whether a nested path exists.
+
+- `Dumas JSON Remove Key`
+  - Inputs: `json_object`, `path`
+  - Output: updated `JSON`
+  - Removes a nested key or array item by path.
+
+- `Dumas JSON Pick Fields`
+  - Inputs: `json_object`, `paths`
+  - Output: filtered `JSON`
+  - Builds a new object from newline-separated paths that exist in the input.
+
 - `Dumas JSON Merge Objects`
   - Inputs: `base_object`, `overlay_object`
   - Output: merged `JSON`
@@ -39,6 +54,16 @@
   - Output: `INT`
   - Returns the length of a JSON array.
 
+- `Dumas JSON Array Append`
+  - Inputs: `json_array`, `value_json`
+  - Output: updated `JSON`
+  - Appends a parsed JSON value to the end of an array.
+
+- `Dumas JSON Array Slice`
+  - Inputs: `json_array`, `start`, `end`, `step`
+  - Output: sliced `JSON`
+  - Returns an array slice. `end=0` means "slice to the end".
+
 - `Dumas JSON Array Iterator`
   - Inputs: `json_input`, `index`, `mode`
   - Outputs: `item`, `current_index`, `total_items`
@@ -49,6 +74,16 @@
   - Outputs: `key`, `value`, `current_index`, `total_items`
   - Returns the current object entry in insertion order, with `mode` set to `fixed`, `incr`, or `decr`.
 
+- `Dumas JSON Flatten`
+  - Input: `json_input`
+  - Output: flat `JSON`
+  - Flattens nested objects and arrays into dot-path keys.
+
+- `Dumas JSON Unflatten`
+  - Input: `flat_json_object`
+  - Output: nested `JSON`
+  - Rebuilds nested JSON from a flat dot-path object.
+
 All nodes live in the `Dumas/JSON` category.
 
 ## Installation
@@ -87,6 +122,16 @@ settings.render.width
 {"enabled": true, "retries": 3}
 ```
 
+`Dumas JSON Pick Fields` expects one path per line:
+
+```text
+user.name
+meta.active
+items.0.id
+```
+
+`Dumas JSON Array Slice` treats `end=0` as "use the rest of the array".
+
 `Dumas JSON Array Iterator` clamps to valid bounds:
 
 ```text
@@ -97,6 +142,8 @@ decr  -> use index - 1
 
 `Dumas JSON Object Iterator` uses the same index rules and iterates object entries in their existing key order.
 
+`Dumas JSON Flatten` and `Dumas JSON Unflatten` use the same dot-path format as the other path-based nodes.
+
 ## Roadmap
 
 This repo is intended to grow into a broader set of Dumas-branded generic utility nodes, including JSON helpers and adjacent data-manipulation tools.