fix: replace personal filesystem paths with env vars / config

- docker-compose.yml: hardcoded iCloud Obsidian vault volume → ${OMBRE_HOST_VAULT_DIR:-./buckets}
- write_memory.py / migrate_to_domains.py / reclassify_domains.py / reclassify_api.py:
  hardcoded ~/Documents/Obsidian Vault/Ombre Brain → OMBRE_BUCKETS_DIR > load_config() > ./buckets
- write_memory.py: also fix B-04 regression (activation_count: 1 → 0 in frontmatter template)
- reclassify_api.py: model + base_url now read from config (was hardcoded SiliconFlow / DeepSeek-V3)
- tests/dataset.py + test_feel_flow.py: anonymize fixture identifiers (P酱/P0lar1s/北极星 → TestUser/北方)

Project identifiers (git.p0lar1s.uk, p0luz/ombre-brain, P0luz/Ombre-Brain GitHub) intentionally retained as project branding per user decision.

tests/test_feel_flow.py

@@ -67,7 +67,7 @@ class TestFeelLifecycle:
         bm, dh, de, bd = isolated_tools
 
         bid = await bm.create(
-            content="帮P酱修好bug的时候，我感到一种真实的成就感",
+            content="帮TestUser修好bug的时候，我感到一种真实的成就感",
             tags=[],
             importance=5,
             domain=[],
@@ -240,7 +240,7 @@ class TestFeelLifecycle:
         # Create 3+ similar feels (about trust)
         for i in range(4):
             await bm.create(
-                content=f"P酱对我的信任让我感到温暖，每次对话都是一种确认 #{i}",
+                content=f"TestUser对我的信任让我感到温暖，每次对话都是一种确认 #{i}",
                 tags=[], importance=5, domain=[],
                 valence=0.8, arousal=0.4,
                 name=None, bucket_type="feel",