refactor: replace type: ignore pragmas with proper type narrowing

- common/config.py: use cast(str, var) after the missing-vars ValueError
  guard to narrow str | None to str for mypy without assert (which bandit
  B101 would flag); removes 24 type: ignore comments across all five
  from_env() classmethod implementations
- common/health_server.py: replace bare type: ignore with
  cast("HealthServer", self.server) to express the invariant that
  HealthHandler is only ever used with HealthServer
- schema-init/schema_init.py: widen dict[str, str | int] to dict[str, Any]
  so psycopg **kwargs unpacking satisfies mypy; removes type: ignore[arg-type]

Remaining pragmas are all legitimate suppressions:
- noqa: S104  — intentional 0.0.0.0 binding in containerised services
- noqa: S105  — false positives ("bearer" token type, Discogs URL consts)
- noqa: ARG001 — request: Request required by slowapi rate limiter
- type: ignore[arg-type] on add_exception_handler — slowapi handler has
  exc: RateLimitExceeded vs FastAPI ExceptionHandler exc: Exception

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: SimplicityGuy

common/config.py

@@ -5,7 +5,7 @@
 from os import getenv
 from pathlib import Path
 import sys
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, cast
 import warnings
 
 
@@ -90,10 +90,10 @@ def from_env(cls) -> "GraphinatorConfig":
             raise ValueError(f"Missing required environment variables: {', '.join(missing_vars)}")
 
         return cls(
-            amqp_connection=amqp_connection,  # type: ignore
-            neo4j_address=neo4j_address,  # type: ignore
-            neo4j_username=neo4j_username,  # type: ignore
-            neo4j_password=neo4j_password,  # type: ignore
+            amqp_connection=cast("str", amqp_connection),
+            neo4j_address=cast("str", neo4j_address),
+            neo4j_username=cast("str", neo4j_username),
+            neo4j_password=cast("str", neo4j_password),
         )
 
 
@@ -132,11 +132,11 @@ def from_env(cls) -> "TableinatorConfig":
             raise ValueError(f"Missing required environment variables: {', '.join(missing_vars)}")
 
         return cls(
-            amqp_connection=amqp_connection,  # type: ignore
-            postgres_address=postgres_address,  # type: ignore
-            postgres_username=postgres_username,  # type: ignore
-            postgres_password=postgres_password,  # type: ignore
-            postgres_database=postgres_database,  # type: ignore
+            amqp_connection=cast("str", amqp_connection),
+            postgres_address=cast("str", postgres_address),
+            postgres_username=cast("str", postgres_username),
+            postgres_password=cast("str", postgres_password),
+            postgres_database=cast("str", postgres_database),
         )
 
 
@@ -431,11 +431,11 @@ def from_env(cls) -> "ApiConfig":
         oauth_encryption_key = getenv("OAUTH_ENCRYPTION_KEY") or None
 
         return cls(
-            postgres_address=postgres_address,  # type: ignore[arg-type]
-            postgres_username=postgres_username,  # type: ignore[arg-type]
-            postgres_password=postgres_password,  # type: ignore[arg-type]
-            postgres_database=postgres_database,  # type: ignore[arg-type]
-            jwt_secret_key=jwt_secret_key,  # type: ignore[arg-type]
+            postgres_address=cast("str", postgres_address),
+            postgres_username=cast("str", postgres_username),
+            postgres_password=cast("str", postgres_password),
+            postgres_database=cast("str", postgres_database),
+            jwt_secret_key=cast("str", jwt_secret_key),
             redis_url=redis_url,
             jwt_algorithm=jwt_algorithm,
             jwt_expire_minutes=jwt_expire_minutes,
@@ -503,13 +503,13 @@ def from_env(cls) -> "CuratorConfig":
         cors_origins = [o.strip() for o in cors_origins_env.split(",") if o.strip()] if cors_origins_env else None
 
         return cls(
-            postgres_address=postgres_address,  # type: ignore[arg-type]
-            postgres_username=postgres_username,  # type: ignore[arg-type]
-            postgres_password=postgres_password,  # type: ignore[arg-type]
-            postgres_database=postgres_database,  # type: ignore[arg-type]
-            neo4j_address=neo4j_address,  # type: ignore[arg-type]
-            neo4j_username=neo4j_username,  # type: ignore[arg-type]
-            neo4j_password=neo4j_password,  # type: ignore[arg-type]
+            postgres_address=cast("str", postgres_address),
+            postgres_username=cast("str", postgres_username),
+            postgres_password=cast("str", postgres_password),
+            postgres_database=cast("str", postgres_database),
+            neo4j_address=cast("str", neo4j_address),
+            neo4j_username=cast("str", neo4j_username),
+            neo4j_password=cast("str", neo4j_password),
             discogs_user_agent=discogs_user_agent,
             cors_origins=cors_origins,
         )
@@ -550,9 +550,9 @@ def from_env(cls) -> "ExploreConfig":
         jwt_secret_key = getenv("JWT_SECRET_KEY") or None
 
         return cls(
-            neo4j_address=neo4j_address,  # type: ignore
-            neo4j_username=neo4j_username,  # type: ignore
-            neo4j_password=neo4j_password,  # type: ignore
+            neo4j_address=cast("str", neo4j_address),
+            neo4j_username=cast("str", neo4j_username),
+            neo4j_password=cast("str", neo4j_password),
             jwt_secret_key=jwt_secret_key,
         )
 

common/health_server.py

@@ -6,7 +6,7 @@
 import json
 import logging
 from threading import Thread
-from typing import Any
+from typing import Any, cast
 
 
 logger = logging.getLogger(__name__)
@@ -19,7 +19,7 @@ def do_GET(self) -> None:
         """Handle GET requests."""
         if self.path == "/health":
             # Get health data from the server instance
-            health_data = self.server.get_health_data()  # type: ignore
+            health_data = cast("HealthServer", self.server).get_health_data()
 
             self.send_response(200)
             self.send_header("Content-Type", "application/json")

schema-init/schema_init.py

@@ -14,6 +14,7 @@
 import os
 import sys
 from pathlib import Path
+from typing import Any
 
 import psycopg
 import structlog
@@ -42,7 +43,7 @@
 POSTGRES_DATABASE = os.environ.get("POSTGRES_DATABASE", "discogsography")
 
 
-def _postgres_connection_params() -> dict[str, str | int]:
+def _postgres_connection_params() -> dict[str, Any]:
     """Parse POSTGRES_ADDRESS into psycopg connection params."""
     if ":" in POSTGRES_ADDRESS:
         host, port_str = POSTGRES_ADDRESS.split(":", 1)
@@ -62,11 +63,11 @@ def _postgres_connection_params() -> dict[str, str | int]:
 # ── PostgreSQL ────────────────────────────────────────────────────────────────
 
 
-def _ensure_postgres_database(params: dict[str, str | int]) -> None:
+def _ensure_postgres_database(params: dict[str, Any]) -> None:
     """Create the target database if it does not already exist (synchronous)."""
     admin_params = {**params, "dbname": "postgres"}
     logger.info("🔧 Ensuring PostgreSQL database exists...", database=POSTGRES_DATABASE)
-    with psycopg.connect(**admin_params) as conn:  # type: ignore[arg-type]
+    with psycopg.connect(**admin_params) as conn:
         conn.autocommit = True
         with conn.cursor() as cursor:
             cursor.execute(