chore: sync main hotfixes into release/3.2.0 (#763)

* fix: disambiguate hook block reasons to name MemPalace explicitly (#666)

Replace "your memory system" with explicit MemPalace references and
tool names (mempalace_diary_write, mempalace_add_drawer, mempalace_kg_add)
in stop and precompact hook block reasons. This prevents Claude Code from
misinterpreting the hook as a native auto-memory save instruction.

Updated in both Python (hooks_cli.py) and standalone shell scripts.

Also fix CONTRIBUTING.md Getting Started to show the fork-first workflow,
matching the PR Guidelines section.

* fix: remove chromadb <0.7 upper bound — blocks 1.x installs

The current constraint `chromadb>=0.5.0,<0.7` forces pip to install
chromadb 0.6.x, but palaces created with chromadb 1.x (which is what
the mempalace dev environment actually uses — 1.5.7 per uv.lock) have
an incompatible SQLite schema. Specifically, chromadb 0.6.x fails with
`KeyError: '_type'` when opening a collection written by 1.x.

This means a fresh `pip install mempalace` gives users a chromadb
version that cannot read palaces created in the maintainer's own
environment. The fix removes the upper bound so pip can resolve to the
current stable chromadb release.

Reproduction:
  python3 -m venv .venv && source .venv/bin/activate
  pip install mempalace          # installs chromadb 0.6.3
  # Try opening a palace created with chromadb 1.x:
  # -> _get_collection() returns None, tool_status() returns "No palace found"
  pip install chromadb==1.5.7    # force upgrade
  # -> tool_status() returns real data (26k drawers in our case)

---------

Co-authored-by: z3tz3r0 <kittipan.wang@gmail.com>
Co-authored-by: AlyciaBHZ <50111876+AlyciaBHZ@users.noreply.github.com>
Co-authored-by: Ben Sigman <1872138+bensig@users.noreply.github.com>

CONTRIBUTING.md

@@ -5,8 +5,11 @@ Thanks for wanting to help. MemPalace is open source and we welcome contribution
 ## Getting Started
 
 ```bash
-git clone https://github.com/MemPalace/mempalace.git
+# Fork the repo on GitHub first, then clone your fork
+git clone https://github.com/<your-username>/mempalace.git
 cd mempalace
+git remote add upstream https://github.com/MemPalace/mempalace.git
+
 pip install -e ".[dev]"    # installs with dev dependencies (pytest, build, twine)
 ```