docs: Added documentation for the new memory functions for deleting and renaming memory files

Memory.md

@@ -95,11 +95,22 @@ Each drill file has YAML frontmatter:
 name: project_compliance
 description: Compliance constraints driving the auth rewrite
 type: project
+created: 2026-05-12
+updated: 2026-07-03
 ---
 
 We must store session tokens server-side per the 2026 audit. ...
 ```
 
+`created` and `updated` are stamped automatically by `memory__write` (creation date is preserved across overwrites). 
+Two more optional fields track staleness:
+
+- `superseded_by: <name>` - this memory has been replaced by another drill file
+- `expires: YYYY-MM-DD` - this memory stops being true after a known date (e.g. an API freeze window)
+
+Both are settable via optional arguments to `memory__write`, and `memory__lint` flags superseded and expired files so 
+the LLM (or you) can clean them up.
+
 `MEMORY.md` is what gets injected on every prompt. It serves two purposes:
 1. **An index** of available drill files (one line per file: name + description)
 2. **A home for universal facts** the LLM should always see (user identity, hard rules, binding feedback)
@@ -124,10 +135,16 @@ categorize its own writes and so you can grep by category.
 When function calling is enabled, coyote exposes:
 
 - `memory__read(name)`: read a specific drill file by its slug
-- `memory__write(name, description, content, scope, type)`: create or replace a drill file (`scope`: `global` | 
-  `workspace`)
+- `memory__write(name, description, content, scope, type, superseded_by?, expires?)`: create or replace a drill file 
+  (`scope`: `global` | `workspace`). Timestamps are stamped automatically; the response reports whether an existing 
+  file was replaced (and its previous description) so accidental overwrites are visible.
+- `memory__rename(name, new_name, scope)`: rename a drill file. Its `MEMORY.md` entry and every `[[wikilink]]` to it 
+  in other memory files are rewritten automatically.
+- `memory__delete(name, scope)`: delete a drill file and remove its `MEMORY.md` entry. Reports any `[[wikilinks]]` in 
+  other files left dangling by the deletion.
 - `memory__list()`: see all known drill files with metadata
-- `memory__lint()`: health-check (orphans, broken `[[wikilinks]]`, oversized files >2K chars)
+- `memory__lint()`: health-check (orphans, broken `[[wikilinks]]`, oversized files >2K chars, stale files that are 
+  superseded or expired, and index descriptions that drifted from the file's own `description:`)
 
 The LLM is instructed to update `MEMORY.md` whenever it writes a new file. Two silent promotions can happen on a 
 `memory__write(scope=workspace)`: