feat: MCP-Leseserver, Bibliotheksgrenze, Haertung des Lesepfads, Publish-Remote-Gate scharf (2.4.0)

Files changed:
- .gitea/workflows/ci.yml
- CHANGES.md
- README.md
- VERSION
- instructions/mcp-read-server.md
- tools/CONTRACT.md
- tools/README.md
- tools/chemenu/api.py
- tools/chemenu/commands/doctor.py
- tools/chemenu/commands/lint.py
- tools/chemenu/commands/search.py
- tools/chemenu/commands/types_cmd.py
- tools/chemenu/config.py
- tools/chemenu/corpus_cache.py
- tools/chemenu/errors.py
- tools/chemenu/frontmatter_io.py
- tools/chemenu/lint_core.py
- tools/chemenu/mcp/__init__.py
- tools/chemenu/mcp/__main__.py
- tools/chemenu/mcp/server.py
- tools/chemenu/page.py
- tools/chemenu/search/filters.py
- tools/chemenu/search/registry.py
- tools/chemenu/search/ripgrep.py
- tools/chemenu/search/service.py
- tools/chemenu/tests/conftest.py
- tools/chemenu/tests/test_api.py
- tools/chemenu/tests/test_corpus_cache.py
- tools/chemenu/tests/test_doctor.py
- tools/chemenu/tests/test_frontmatter_io.py
- tools/chemenu/tests/test_instructions_cmd.py
- tools/chemenu/tests/test_mcp_server.py
- tools/chemenu/tests/test_new_page.py
- tools/chemenu/tests/test_search.py
- tools/chemenu/type_resolver.py
- tools/chemenu/types_core.py
- tools/requirements-mcp.txt

tools/chemenu/commands/search.py

@@ -21,90 +21,38 @@ Scope is `kb/` only. `instructions/` is discovered through
 from __future__ import annotations
 
 import json
-from pathlib import Path
 
 import typer
 
-from chemenu import config
 from chemenu.commands._util import fail, today_iso
-from chemenu.frontmatter_io import read_page
-from chemenu.kb_scan import iter_kb_pages
-from chemenu.page import Page
 from chemenu.search import filters
-from chemenu.search.base import page_key
 from chemenu.search.filters import PredicateError
-from chemenu.search.fuse import reciprocal_rank_fusion
 from chemenu.search.registry import UnknownBackend, resolve
-from chemenu.search.ripgrep import RipgrepFailed, RipgrepMissing, build_hit
+from chemenu.search.ripgrep import RipgrepFailed, RipgrepMissing
+from chemenu.search.service import (
+    load_pages_by_path,
+    run_search,
+    sort_hits,
+    unreadable_pages,
+)
 from chemenu.search.types import Predicate, SearchHit, SearchQuery
 
+# Re-exported so `from chemenu.commands.search import run_search` keeps
+# resolving. The core lives in `chemenu/search/service.py`, which imports no
+# CLI machinery; this module is the terminal adapter over it.
+__all__ = [
+    "load_pages_by_path",
+    "run_search",
+    "sort_hits",
+    "unreadable_pages",
+    "render_table",
+    "search_command",
+]
+
 TITLE_WIDTH = 34
 SUMMARY_WIDTH = 84
 
 
-def load_pages_by_path(kb_dir: Path | None = None, root: Path | None = None) -> dict[str, Page]:
-    """Every page under `kb/`, keyed by repo-relative path.
-
-    Path-keyed rather than title-keyed on purpose: `load_kb_pages()` drops one
-    of two pages sharing a stem, and search should still find both - a
-    duplicate title is a lint finding, not a reason to hide a page.
-    """
-    kb_dir = kb_dir or config.KB_DIR
-    root = root or config.ROOT
-    pages: dict[str, Page] = {}
-    for path in iter_kb_pages(kb_dir):
-        frontmatter, body = read_page(path)
-        pages[page_key(path, root)] = Page(path=path, frontmatter=frontmatter, body=body)
-    return pages
-
-
-def _sort_key(hit: SearchHit, field: str):
-    value = hit.as_dict().get(field)
-    if value is None:
-        # Missing values sort last in either direction rather than crashing on
-        # a None comparison.
-        return (1, "")
-    if isinstance(value, (int, float)):
-        return (0, value)
-    return (0, str(value).lower())
-
-
-def sort_hits(hits: list[SearchHit], sort: str | None) -> list[SearchHit]:
-    """Sort by a hit field. A leading `-` reverses, e.g. `--sort -confidence`."""
-    if not sort:
-        return hits
-    descending = sort.startswith("-")
-    field = sort.lstrip("-")
-    ordered = sorted(hits, key=lambda h: _sort_key(h, field), reverse=descending)
-    return ordered
-
-
-def run_search(
-    query: SearchQuery,
-    pages: dict[str, Page],
-    backends: list,
-    kb_dir: Path | None = None,
-) -> list[SearchHit]:
-    """Answer a query. Pure: no I/O beyond whatever a backend does."""
-    filters.validate_fields(query.predicates, pages)
-
-    if query.text:
-        rankings = [backend.search(query, pages) for backend in backends]
-        hits = rankings[0] if len(rankings) == 1 else reciprocal_rank_fusion(rankings)
-        allowed = filters.apply_predicates(pages, query.predicates, kb_dir)
-        hits = [hit for hit in hits if hit.path in allowed]
-    else:
-        selected = filters.apply_predicates(pages, query.predicates, kb_dir)
-        hits = [
-            build_hit(page, key, [], query, backend="frontmatter", kb_dir=kb_dir)
-            for key, page in selected.items()
-        ]
-        hits.sort(key=lambda h: h.title.lower())
-
-    hits = sort_hits(hits, query.sort)
-    return hits[: query.limit] if query.limit else hits
-
-
 def _truncate(text: str, width: int) -> str:
     text = " ".join(text.split())
     return text if len(text) <= width else text[: width - 1] + "\u2026"
@@ -206,6 +154,8 @@ def search_command(
     except RipgrepFailed as exc:
         fail(str(exc))
 
+    unreadable = unreadable_pages(pages)
+
     if json_out:
         payload = {
             "generated": today_iso(),
@@ -214,8 +164,17 @@ def search_command(
             "backend": ",".join(b.name for b in backends),
             "count": len(hits),
             "results": [hit.as_dict() for hit in hits],
+            # Always present, usually empty. A caller that has to look for the
+            # key to learn whether it should worry will not look.
+            "unreadable": unreadable,
         }
         typer.echo(json.dumps(payload, indent=2))
         return
 
     typer.echo(render_table(hits, show_matches))
+    for entry in unreadable:
+        typer.echo(
+            f"WARN unreadable frontmatter: {entry['path']} ({entry['reason']}) - "
+            "this page cannot match any --field predicate",
+            err=True,
+        )