feat(hashline-edit): add anchor insert modes and strict insert validation

src/tools/hashline-edit/tool-description.ts

@@ -0,0 +1,34 @@
+export const HASHLINE_EDIT_DESCRIPTION = `Edit files using LINE#ID format for precise, safe modifications.
+
+WORKFLOW:
+1. Read the file and copy exact LINE#ID anchors.
+2. Submit one edit call with all related operations for that file.
+3. If more edits are needed after success, use the latest anchors from read/edit output.
+4. Use anchors as "LINE#ID" only (never include trailing ":content").
+
+VALIDATION:
+- Payload shape: { "filePath": string, "edits": [...], "delete"?: boolean, "rename"?: string }
+- Each edit must be one of: set_line, replace_lines, insert_after, insert_before, insert_between, replace
+- text/new_text must contain plain replacement text only (no LINE#ID prefixes, no diff + markers)
+
+LINE#ID FORMAT (CRITICAL - READ CAREFULLY):
+Each line reference must be in "LINE#ID" format where:
+- LINE: 1-based line number
+- ID: Two CID letters from the set ZPMQVRWSNKTXJBYH
+
+OPERATION TYPES:
+1. set_line
+2. replace_lines
+3. insert_after
+4. insert_before
+5. insert_between
+6. replace
+
+FILE MODES:
+- delete=true deletes file and requires edits=[] with no rename
+- rename moves final content to a new path and removes old path
+
+CONTENT FORMAT:
+- text/new_text can be a string (single line) or string[] (multi-line, preferred).
+- If you pass a multi-line string, it is split by real newline characters.
+- Literal "\\n" is preserved as text.`