SP-Zugriffsweg explizit (access: api/snapshot, #133) und follow_up_at-Korrektur (dueWithTime/dueDay, #135)

Files changed:
- CHANGES.md
- INSTALL.md
- VERSION
- tools/CONTRACT.md
- tools/chemenu/commands/doctor.py
- tools/chemenu/commands/new_page.py
- tools/chemenu/commands/review_cmd.py
- tools/chemenu/review.py
- tools/chemenu/tasks/__init__.py
- tools/chemenu/tasks/config.py
- tools/chemenu/tasks/protocol.py
- tools/chemenu/tasks/superproductivity.py
- tools/chemenu/tests/test_doctor.py
- tools/chemenu/tests/test_new_page.py
- tools/chemenu/tests/test_review.py
- tools/chemenu/tests/test_superproductivity.py
- tools/chemenu/tests/test_tasks_config.py

tools/chemenu/tasks/__init__.py

@@ -24,11 +24,16 @@ from chemenu.tasks.protocol import TaskReader, TaskWriter
 
 
 def build_reader(cfg: TasksConfig) -> TaskReader:
-    """Dispatch on `cfg.provider` to a concrete `TaskReader`."""
+    """Dispatch on `cfg.provider` to a concrete `TaskReader`. For
+    `superproductivity` the concrete class also depends on
+    `access` (Gitea #133): `"api"` reads the live local REST API,
+    `"snapshot"` reads the backup file - never both, never a fallback."""
     if cfg.provider == "superproductivity":
         from chemenu.tasks import superproductivity as sp
 
         sp_cfg = sp.SuperProductivityConfig.from_dict(cfg.provider_config)
+        if sp_cfg.access == sp.ACCESS_API:
+            return sp.SuperProductivityApiReader(sp_cfg)
         return sp.SuperProductivityReader(sp_cfg)
     raise ValidationError(f"No reader is wired up for task provider {cfg.provider!r}.")
 
@@ -37,10 +42,23 @@ def build_writer(cfg: TasksConfig, reader: TaskReader) -> TaskWriter:
     """Dispatch on `cfg.provider` to a concrete `TaskWriter`, over an
     already-built `reader` - a writer that needs to re-check the read path
     (e.g. `SuperProductivityWriter`'s own collision preflight) reads through
-    the same object its caller does, rather than opening a second one."""
+    the same object its caller does, rather than opening a second one.
+
+    For `superproductivity`, a writer exists only when `access: "api"`
+    (Gitea #133): on `access: "snapshot"` the tracker is read-only from here
+    by construction, so this raises `ValidationError` rather than returning a
+    writer that could never do anything - the same posture as "no writer is
+    wired up for this provider at all", just scoped to one access mode of
+    one provider instead of the whole provider."""
     if cfg.provider == "superproductivity":
         from chemenu.tasks import superproductivity as sp
 
         sp_cfg = sp.SuperProductivityConfig.from_dict(cfg.provider_config)
+        if sp_cfg.access != sp.ACCESS_API:
+            raise ValidationError(
+                "superproductivity: the tracker is read-only from here (access: "
+                f"'{sp_cfg.access}') - the write path only exists on an access: 'api' "
+                "instance (Gitea #133)."
+            )
         return sp.SuperProductivityWriter(sp_cfg, reader)
     raise ValidationError(f"No writer is wired up for task provider {cfg.provider!r}.")