information_schema.columns and pg_attribute report nothing for views

[erans]

Problem

information_schema.columns and pg_attribute both report nothing for views. Each restricts to type = 'table':

• information_schema_columns (migration v29, src/migration/registry.rs) — WHERE m.type = 'table'
• pg_attribute (migration v26) — same restriction

This is longstanding behavior, unchanged by #103 (which rebuilt information_schema_columns but deliberately preserved the restriction to avoid widening that change's blast radius). The Rust handler #103 deleted had the same limitation, so nothing regressed — but nothing improved either.

Why it matters

Real PostgreSQL reports view columns in both surfaces. ORMs use this for view reflection: SQLAlchemy's Inspector.get_columns() works on views, and Django's inspectdb will discover a view but generate a model with no fields.

What to do

Extend both to type IN ('table', 'view').

The interesting part is type resolution. A view's columns have no PRAGMA table_info declared type in the useful sense — SQLite reports empty strings for expression columns — and no __pgsqlite_schema rows at all, since that table is populated at CREATE TABLE time. Options worth weighing:

1. Report text for every view column (honest, cheap, matches the current ELSE 'text' fallback).
2. Resolve through PRAGMA table_info where SQLite infers a type from a passthrough column, falling back to text.
3. Trace simple SELECT col FROM t views back to the base table's __pgsqlite_schema entry.

(3) is the only one that gets NUMERIC/UUID/JSONB right on a view, but it needs view-body parsing and stops working the moment an expression is involved.

Notes

• __pgsqlite_pg_data_type and the other UDFs from fix: namespace-aware information_schema served from SQLite (#88) #103 are already available in SQL, so whatever mapping is chosen is reachable from the view body.
• Whichever approach is taken, data_type must never report integer for a TIMESTAMPTZ column — that leaks pgsqlite's internal INTEGER datetime storage onto a client-visible surface. fix: namespace-aware information_schema served from SQLite (#88) #103 has a test asserting this for tables; extend it to views.
• Split out of information_schema.tables lists pgsqlite's materialized pg_* and information_schema_* relations #88 / fix: namespace-aware information_schema served from SQLite (#88) #103.