docs: add write_note safety warnings to memory-notes and memory-reflect skills

write_note silently overwrites existing notes. Agents need clear
guidance to use edit_note for files that accumulate content (daily
notes, MEMORY.md, logs). This prevents accidental data loss.

Refs: basicmachines-co/basic-memory#625

Author: bm-clawd

skills/memory-notes/SKILL.md

@@ -248,3 +248,28 @@ edit_note(
 6. **Link related concepts.** The value of a knowledge graph compounds with connections. A note with zero relations is an island — useful, but not as powerful as a connected one.
 
 7. **Let the graph grow naturally.** Don't try to design a perfect taxonomy upfront. Write notes as you work, add relations as connections emerge, and periodically use `/reflect` or `/defrag` to consolidate.
+
+## ⚠️ write_note vs edit_note — Avoiding Data Loss
+
+**`write_note` is destructive.** If a note with the same title already exists, `write_note` silently replaces it. This will destroy accumulated content in daily notes, logs, or any file that grows over time.
+
+### Rules
+
+- **New notes**: Use `write_note` — it creates the file and frontmatter correctly.
+- **Existing notes**: Use `edit_note` — it modifies without replacing.
+  - `operation: "append"` — add content to the end
+  - `operation: "prepend"` — add content to the beginning
+  - `operation: "find_replace"` — surgical text replacement
+  - `operation: "replace_section"` — replace a specific heading section
+
+### Common Mistake
+
+```
+# ❌ WRONG — destroys existing daily note content
+write_note(title="2026-02-26", folder="memory", content="## New Section\n...")
+
+# ✅ RIGHT — appends to existing daily note
+edit_note(identifier="2026-02-26", operation="append", content="\n## New Section\n...")
+```
+
+**When in doubt, use `edit_note`.** It's always safe. `write_note` is only safe when you're certain the note doesn't exist yet or you intentionally want to replace it entirely.

skills/memory-reflect/SKILL.md

@@ -61,3 +61,18 @@ Append a brief entry to today's daily note:
 - **Flag uncertainty.** If something seems important but you're not sure, add it with a note like "(needs confirmation)" rather than skipping it entirely.
 - **Restructure over time.** If MEMORY.md is a chronological dump, restructure it into topical sections during reflection. Curated knowledge > raw logs.
 - **Check for filesystem issues.** Look for recursive nesting (memory/memory/memory/...), orphaned files, or bloat while gathering material.
+
+## ⚠️ Safe Writing Pattern
+
+**Never use `write_note` on daily notes or MEMORY.md.** These files accumulate content throughout the day. `write_note` replaces the entire file — use `edit_note` instead:
+
+```
+# ✅ Update a section in MEMORY.md
+edit_note(identifier="MEMORY", operation="replace_section", section="About Me", content="...")
+
+# ✅ Append reflection log to today's daily note
+edit_note(identifier="2026-02-26", operation="append", content="\n## Reflection (22:00)\n...")
+
+# ❌ NEVER do this — destroys the existing file
+write_note(title="2026-02-26", folder="memory", content="...")
+```