feat: sharing tests, property tests, tag-share UI, inline errors, route fix

- Add 10 sharing endpoint tests (share/unshare memory, tag shares, shared-with-me,
  my-shares, recall with shared, update permission checks)
- Add hypothesis property-based tests for model validation (roundtrip, bounds,
  enum, sort_by, limit)
- Tighten model validation: sort_by Literal, limit ge=1/le=500, tags/keywords max_length
- Fix dashboard shared_with_me stat to include tag-based shares
- Add tag-sharing management UI (share/remove tags, user typeahead)
- Replace alert() with inline error messages
- Fix route ordering bug: share-tag routes before {memory_id} parameterized routes

src/claude_memory/api/models.py

@@ -9,8 +9,8 @@ MAX_MEMORY_CHARS = 800
 class MemoryStore(BaseModel):
     content: str = Field(..., max_length=MAX_MEMORY_CHARS)
     category: str = "facts"
-    tags: str = ""
-    expanded_keywords: str = ""
+    tags: str = Field(default="", max_length=500)
+    expanded_keywords: str = Field(default="", max_length=500)
     importance: float = Field(default=0.5, ge=0.0, le=1.0)
     force_sensitive: bool = False
 
@@ -19,8 +19,8 @@ class MemoryRecall(BaseModel):
     context: str
     expanded_query: str = ""
     category: Optional[str] = None
-    sort_by: str = "importance"
-    limit: int = 10
+    sort_by: Literal["importance", "relevance", "recency"] = "importance"
+    limit: int = Field(default=10, ge=1, le=500)
 
 
 class MemoryResponse(BaseModel):