feat: removed chunk-mode modules and read/edit entrypoints from pi-natives

- Removed `pi-natives` chunk language classifier modules and all core chunk subsystems (kind, state, render, edit, resolve).
- Removed chunk-mode CLI/read/edit entrypoints, including `read` command and chunk mode registration/prompt tooling.
- Removed chunk selectors from `read` and `grep` tools, switching behavior to raw/L-range handling.
- Fixed poll wait parsing to keep defaulting to `30s` when the provided value is empty.

scripts/edit-benchmark.py

@@ -2,11 +2,10 @@
 """
 Edit benchmark: tests the edit tool across models with a simple edit task.
 
-Select the edit variant via the PI_EDIT_VARIANT env var (e.g. `chunk`, `vim`,
+Select the edit variant via the PI_EDIT_VARIANT env var (e.g. `vim`,
 `hashline`, `replace`, `patch`, `apply_patch`) or `--variant`.
 
 Examples:
-	PI_EDIT_VARIANT=chunk scripts/edit-benchmark.py
 	PI_EDIT_VARIANT=vim   scripts/edit-benchmark.py
 	scripts/edit-benchmark.py --variant hashline
 """
@@ -54,11 +53,7 @@ def build_spec(variant: str) -> BenchmarkSpec:
 		f"```rust\n"
 		f"{EXPECTED_CONTENT}```\n"
 	)
-	retry = (
-		'Use `read(path="test.rs")` to refresh chunk selectors if needed, then try again using the edit tool.'
-		if variant == "chunk"
-		else f"Please try again using the edit tool {mode_phrase}."
-	)
+	retry = f"Please try again using the edit tool {mode_phrase}."
 	return BenchmarkSpec(
 		description=f"Benchmark edit tool in {variant} mode across models with simple edit tasks.",
 		workspace_prefix=f"{variant}-benchmark",

scripts/rate-edit-tool.py

@@ -720,7 +720,7 @@ MARKDOWN_FIXTURE = (
 
     | Surface | Expected stress |
     | --- | --- |
-    | `main.ts` | Structural chunk addressing |
+    | `main.ts` | Type/interface and class member edits |
     | `main.rs` | Enum and impl member edits |
     | `main.py` | Indentation-sensitive blocks |
     | `main.md` | Prose and block-level text edits |