fix(infra): pass pgweb credentials via discrete CLI flags

`PGWEB_DATABASE_URL` (post-#62 rename) still failed at boot with:

    Error: Invalid URL. Valid format:
    postgres://user:password@host:port/db?sslmode=mode

The userinfo portion of a Postgres URL must be URL-encoded —
any `@`, `#`, `:`, `/`, `?`, `%`, `&`, `=`, `+`, `;` etc. in the
password breaks the parser. Compose has no built-in URL encoding,
so the URL we construct in YAML is fragile by design.

Switch to pgweb's discrete CLI flags (`--host`, `--port`, `--user`,
`--pass`, `--db`, `--ssl`). Compose interpolates each value
literally — no URL encoding required, any password works. The
image's ENTRYPOINT already passes `--bind=0.0.0.0 --listen=8081`;
our args are appended to those.

Side benefit: the failure mode for a missing password is now an
explicit Compose error
(`POSTGRES_PASSWORD must be set in infra/local/.env`) rather than
an opaque pgweb crash.

infra/local/dev.compose.yml

@@ -102,11 +102,20 @@ services:
     container_name: apf-portal-pgweb
     restart: unless-stopped
     profiles: [dbtools]
-    environment:
-      # `PGWEB_DATABASE_URL` (formerly `DATABASE_URL`) — pgweb 0.16
-      # deprecated the old name, ignores it, and starts up empty,
-      # crashing with "Invalid URL".
-      PGWEB_DATABASE_URL: postgres://${POSTGRES_USER:-portal}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB:-portal_dev}?sslmode=disable
+    # Use discrete CLI flags rather than `PGWEB_DATABASE_URL`. The URL
+    # form is fragile: any special character in POSTGRES_PASSWORD
+    # (`@`, `#`, `:`, `/`, `?`, `%`, `&`, …) breaks the userinfo
+    # parser, and the resulting "Invalid URL" error is opaque. Discrete
+    # flags accept any password verbatim. The image's ENTRYPOINT
+    # already passes `--bind=0.0.0.0 --listen=8081`; these args are
+    # appended.
+    command:
+      - --host=postgres
+      - --port=5432
+      - --user=${POSTGRES_USER:-portal}
+      - --pass=${POSTGRES_PASSWORD:?POSTGRES_PASSWORD must be set in infra/local/.env}
+      - --db=${POSTGRES_DB:-portal_dev}
+      - --ssl=disable
     ports:
       - '${PGWEB_PORT:-8081}:8081'
     depends_on: