test: add pytest suite - 97 tests, search + indexer + auth

Create comprehensive test suite with 97 passing tests:
- tests/conftest.py: fixtures (TestClient, temp vault dirs, index setup)
- tests/test_search.py (27 tests): tokenizer, snippets, highlight,
  tag filter, search API, advanced search, suggest, tags API
- tests/test_indexer.py (32 tests): frontmatter parsing, inline tags,
  title extraction, scan_vault, find_file_in_index, backlinks
- tests/test_auth.py (38 tests): password hashing, JWT create/decode,
  token revocation, user CRUD, login lockout, rate limiting, middleware

Also fix: lazy WeasyPrint import (graceful fallback when GTK missing),
add data/ to .gitignore (runtime files from test runs).

tests/test_indexer.py

@@ -0,0 +1,284 @@
+# tests/test_indexer.py — Tests for the indexer module
+import os
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from backend.indexer import (
+    _extract_tags,
+    _extract_inline_tags,
+    _extract_title,
+    parse_markdown_file,
+    find_file_in_index,
+    get_vault_names,
+    get_vault_data,
+    get_backlinks,
+    get_conflicts,
+    SUPPORTED_EXTENSIONS,
+    _scan_vault,
+    load_vault_config,
+)
+
+
+# ═══════════════════════════════════════════════════════════════════
+# _extract_tags
+# ═══════════════════════════════════════════════════════════════════
+
+class TestExtractTags:
+    def test_list_of_tags(self):
+        import frontmatter
+        post = frontmatter.loads("---\ntags:\n  - python\n  - docker\n---\n# Hello")
+        tags = _extract_tags(post)
+        assert tags == ["python", "docker"]
+
+    def test_comma_separated_string(self):
+        import frontmatter
+        post = frontmatter.loads("---\ntags: python, docker, tutorial\n---\n# Hello")
+        tags = _extract_tags(post)
+        assert set(tags) == {"python", "docker", "tutorial"}
+
+    def test_with_hash_prefix(self):
+        import frontmatter
+        post = frontmatter.loads("---\ntags:\n  - '#python'\n  - '#docker'\n---\n# Hello")
+        tags = _extract_tags(post)
+        assert tags == ["python", "docker"]
+
+    def test_empty_tags(self):
+        import frontmatter
+        post = frontmatter.loads("---\ntitle: No Tags\n---\n# Hello")
+        tags = _extract_tags(post)
+        assert tags == []
+
+    def test_none_tags(self):
+        import frontmatter
+        post = frontmatter.Post("# Hello", **{})
+        tags = _extract_tags(post)
+        assert tags == []
+
+
+# ═══════════════════════════════════════════════════════════════════
+# _extract_inline_tags
+# ═══════════════════════════════════════════════════════════════════
+
+class TestExtractInlineTags:
+    def test_simple_tag(self):
+        tags = _extract_inline_tags("Un texte avec un #tag dedans.")
+        assert "tag" in tags
+
+    def test_multiple_tags(self):
+        tags = _extract_inline_tags("#python est cool, #docker aussi.")
+        assert "python" in tags
+        assert "docker" in tags
+
+    def test_no_tags(self):
+        tags = _extract_inline_tags("Juste du texte sans tags.")
+        assert tags == []
+
+    def test_code_block_excluded(self):
+        content = "```python\n# This is a code comment, not a tag\nprint('hello')\n```"
+        tags = _extract_inline_tags(content)
+        assert tags == []
+
+    def test_inline_code_excluded(self):
+        content = "Use `#notatag` in your code."
+        tags = _extract_inline_tags(content)
+        assert tags == []
+
+    def test_mixed(self):
+        content = "#real-tag outside code, `#fake-tag` inside."
+        tags = _extract_inline_tags(content)
+        assert "real-tag" in tags
+        assert "fake-tag" not in tags
+
+    def test_tag_at_line_start(self):
+        tags = _extract_inline_tags("#tag at the start\nof the line.")
+        assert "tag" in tags
+
+
+# ═══════════════════════════════════════════════════════════════════
+# _extract_title
+# ═══════════════════════════════════════════════════════════════════
+
+class TestExtractTitle:
+    def test_from_frontmatter(self):
+        import frontmatter
+        post = frontmatter.loads("---\ntitle: Mon Super Titre\n---\n# Content")
+        title = _extract_title(post, Path("/fake/file.md"))
+        assert title == "Mon Super Titre"
+
+    def test_fallback_to_filename(self):
+        import frontmatter
+        post = frontmatter.Post("# Content", **{})
+        title = _extract_title(post, Path("/fake/my-great-note.md"))
+        assert title == "my great note"
+
+    def test_underscore_fallback(self):
+        import frontmatter
+        post = frontmatter.Post("# Content", **{})
+        title = _extract_title(post, Path("/fake/my_great_note.md"))
+        assert title == "my great note"
+
+
+# ═══════════════════════════════════════════════════════════════════
+# parse_markdown_file
+# ═══════════════════════════════════════════════════════════════════
+
+class TestParseMarkdownFile:
+    def test_valid_frontmatter(self):
+        post = parse_markdown_file("---\ntags:\n  - test\ntitle: Hello\n---\n# Hello\nWorld")
+        assert post.metadata["title"] == "Hello"
+        assert post.metadata["tags"] == ["test"]
+        assert "World" in post.content
+
+    def test_no_frontmatter(self):
+        post = parse_markdown_file("# Just a heading\nNo frontmatter.")
+        assert post.metadata == {}
+        assert "Just a heading" in post.content
+
+    def test_invalid_frontmatter_fallback(self):
+        """Malformed YAML should fall back gracefully."""
+        post = parse_markdown_file("---\ninvalid: [unclosed\n---\n# Content")
+        # Should not raise, should return content
+        assert "Content" in post.content
+
+    def test_empty_file(self):
+        post = parse_markdown_file("")
+        assert post.content == ""
+
+
+# ═══════════════════════════════════════════════════════════════════
+# SUPPORTED_EXTENSIONS
+# ═══════════════════════════════════════════════════════════════════
+
+class TestSupportedExtensions:
+    def test_markdown_is_supported(self):
+        assert ".md" in SUPPORTED_EXTENSIONS
+
+    def test_common_code_extensions(self):
+        for ext in [".py", ".js", ".ts", ".go", ".rs", ".java", ".rb"]:
+            assert ext in SUPPORTED_EXTENSIONS, f"{ext} should be supported"
+
+    def test_config_extensions(self):
+        for ext in [".json", ".yaml", ".yml", ".toml", ".ini", ".cfg", ".conf"]:
+            assert ext in SUPPORTED_EXTENSIONS, f"{ext} should be supported"
+
+    def test_binary_not_supported(self):
+        assert ".png" not in SUPPORTED_EXTENSIONS
+        assert ".exe" not in SUPPORTED_EXTENSIONS
+
+
+# ═══════════════════════════════════════════════════════════════════
+# _scan_vault
+# ═══════════════════════════════════════════════════════════════════
+
+class TestScanVault:
+    def test_scan_creates_file_entries(self, test_vault_dir):
+        result = _scan_vault("TestVault", test_vault_dir)
+        assert len(result["files"]) >= 3  # note1, note2, projet, café_crème, config.json
+        assert len(result["tags"]) > 0
+        assert result["path"] == test_vault_dir
+
+    def test_scan_includes_paths(self, test_vault_dir):
+        result = _scan_vault("TestVault", test_vault_dir)
+        # Should have at least dir + file entries
+        paths = result.get("paths", [])
+        file_paths = [p["path"] for p in paths if p["type"] == "file"]
+        dir_paths = [p["path"] for p in paths if p["type"] == "directory"]
+        assert len(file_paths) >= 3
+        assert any("Projets" in d for d in dir_paths)
+
+    def test_file_has_required_fields(self, test_vault_dir):
+        result = _scan_vault("TestVault", test_vault_dir)
+        f = result["files"][0]
+        assert "path" in f
+        assert "title" in f
+        assert "tags" in f
+        assert "content" in f
+        assert "content_preview" in f
+        assert "size" in f
+        assert "modified" in f
+        assert "extension" in f
+
+    def test_content_is_truncated(self, test_vault_dir):
+        """Content should be capped at SEARCH_CONTENT_LIMIT."""
+        result = _scan_vault("TestVault", test_vault_dir)
+        for f in result["files"]:
+            assert len(f["content"]) <= 100_000  # SEARCH_CONTENT_LIMIT
+
+
+# ═══════════════════════════════════════════════════════════════════
+# Index integration (requires built index)
+# ═══════════════════════════════════════════════════════════════════
+
+class TestIndexIntegration:
+    def test_get_vault_names(self, client):
+        names = get_vault_names()
+        assert "TestVault" in names
+
+    def test_get_vault_data(self, client):
+        data = get_vault_data("TestVault")
+        assert data is not None
+        assert len(data["files"]) >= 3
+
+    def test_find_file_in_index(self, client):
+        # Try finding by filename first
+        result = find_file_in_index("note1.md", "TestVault")
+        if result is None:
+            # Fallback: try by title
+            result = find_file_in_index("Introduction à Python", "TestVault")
+        assert result is not None, f"Could not find note1.md in index. Vaults: {get_vault_names()}"
+        assert result["vault"] == "TestVault"
+
+    def test_find_file_case_insensitive(self, client):
+        result = find_file_in_index("NOTE1.MD", "TestVault")
+        # Case insensitive via filename
+        if result is None:
+            result = find_file_in_index("introduction à python", "TestVault")
+        assert result is not None
+
+    def test_find_file_not_found(self, client):
+        result = find_file_in_index("DoesNotExistXYZ123", "TestVault")
+        assert result is None
+
+    def test_get_backlinks(self, client):
+        # note2.md links to "Introduction à Python" which should resolve to note1.md
+        backlinks = get_backlinks("TestVault", "note1.md")
+        if len(backlinks) == 0:
+            # Try with .md suffix
+            backlinks = get_backlinks("TestVault", "Introduction à Python.md")
+        assert len(backlinks) >= 1, f"Expected backlinks for note1.md, got {backlinks}"
+
+
+# ═══════════════════════════════════════════════════════════════════
+# load_vault_config
+# ═══════════════════════════════════════════════════════════════════
+
+class TestLoadVaultConfig:
+    def test_loads_sequential_vaults(self, test_vault_dir):
+        os.environ["VAULT_1_NAME"] = "V1"
+        os.environ["VAULT_1_PATH"] = test_vault_dir
+        os.environ["VAULT_2_NAME"] = "V2"
+        os.environ["VAULT_2_PATH"] = test_vault_dir
+        config = load_vault_config()
+        assert len(config) == 2
+        assert config["V1"]["path"] == test_vault_dir
+        assert config["V2"]["path"] == test_vault_dir
+
+    def test_stops_at_missing_pair(self, test_vault_dir):
+        os.environ["VAULT_1_NAME"] = "V1"
+        os.environ["VAULT_1_PATH"] = test_vault_dir
+        # VAULT_2_NAME missing — should stop
+        os.environ["VAULT_3_NAME"] = "V3"
+        os.environ["VAULT_3_PATH"] = test_vault_dir
+        config = load_vault_config()
+        assert len(config) == 1
+        assert "V1" in config
+        assert "V3" not in config
+
+    def test_dir_entries(self, test_vault_dir):
+        os.environ["DIR_1_NAME"] = "MyDir"
+        os.environ["DIR_1_PATH"] = test_vault_dir
+        config = load_vault_config()
+        assert "MyDir" in config
+        assert config["MyDir"]["type"] == "DIR"