fix(snowflake): unblock multi-schema ingest and relationship discovery (#204)

* feat(setup): drop redundant Snowflake schema prompt; fall back to free-text on listSchemas failure

Snowflake setup previously asked for a single schema as free text, then
ran a multiselect against the discovered schemas — two schema questions
back-to-back, with the first being only a session bootstrap. The SDK's
`schema` is optional, so the bootstrap step is unnecessary.

- Remove the free-text Snowflake schema prompt; only pass `schema` to
  snowflake-sdk when one is configured.
- When `listSchemas()` fails (e.g. role lacks SHOW SCHEMAS), prompt the
  user for a comma-separated list, persist it as `schema_names`, and use
  it as both the table-list filter and the multiselect default. Applies
  to every driver with a scope-discovery spec, not just Snowflake.
- Update docs to lead with `schema_names`; keep `schema_name` as a
  documented single-schema shorthand.

* fix(snowflake): keep introspecting when primary-key discovery is denied

The PK query joins INFORMATION_SCHEMA.TABLE_CONSTRAINTS and
INFORMATION_SCHEMA.KEY_COLUMN_USAGE, which require grants the
connection role may not have. Previously a 'SQL compilation error:
Object ANALYTICS.INFORMATION_SCHEMA.KEY_COLUMN_USAGE does not exist
or not authorized' aborted the entire introspect — schemas, columns,
and row counts were all discarded over a missing nice-to-have.

Wrap the constraint query in try/catch, log a one-line warning per
schema, and return an empty PK map. Columns end up with
primaryKey=false; relationship inference still has FK and profiling
to fall back on.

* fix(scan): unblock relationship discovery on Snowflake

Two adjacent bugs prevented the scan's relationship pipeline from producing
any joins on a Snowflake warehouse:

- relationship-profiling.ts fell through to a default `GROUP_CONCAT` branch
  for unknown drivers. Snowflake has no GROUP_CONCAT, so every per-table
  profile query failed with "Unknown function GROUP_CONCAT". Add an explicit
  Snowflake branch that uses LISTAGG with a literal '\x1f' delimiter
  (Snowflake requires the delimiter to be a constant, so CHR(31) is rejected).
- description-generation.ts destructured `connector.sampleTable` and
  `connector.sampleColumn` into bare locals, losing the `this` binding when
  the class-method connectors (Snowflake, Postgres, MySQL) were invoked.
  Every sample call threw "Cannot read properties of undefined (reading
  'assertConnection')" and degraded LLM descriptions to metadata-only
  prompts. Call the methods through the connector instead.

Without these, even after the primary-key probe is allowed to fail softly,
the scan ends up with 0 validated relationships and an empty `joins:` block
in every shard YAML.

* test(scan): cover table-ref helpers

* feat(scan): plumb tableScope through live-database introspection port

* feat(scan): apply tableScope during metadata fetch

* feat(scan): enforce table scope at fetch boundary

* feat(scan): pool Snowflake sessions and batch enrichment for faster ingest (#206)

* feat(cli): add RSA key-pair auth option to Snowflake setup wizard

Extends the interactive Snowflake setup flow with an authentication-method
prompt (password vs RSA/JWT key-pair). The RSA branch collects a private-key
path (env/file/absolute) and an optional passphrase; the resulting connection
config records `authMethod: 'rsa'` with `privateKey` and `passphrase` instead
of `password`.

* feat(scan): pool Snowflake sessions

* fix(scan): reuse structural snapshots and cleanup connectors

* feat(scan): parallelize relationship profiling

* feat(scan): batch table description generation

* docs: document Snowflake ingest concurrency knobs

* fix(scan): close Snowflake ingest perf verification gaps

* fix(scan): keep batched description failure bounded

* feat(scan): dispatch query-history probes by connection driver

Extract historic-sql dialect resolution into a shared helper so the
status-project readiness check and the local ingest factory agree on
which connections enable query history and which probe to run. The
status command now picks the postgres/snowflake/bigquery probe based on
the connection's driver instead of always reporting against postgres,
which previously caused snowflake connections with queryHistory.enabled
to surface a misleading "driver is snowflake" failure.

Also drops a noisy console.warn from Snowflake primary-key discovery —
INFORMATION_SCHEMA.KEY_COLUMN_USAGE is commonly ungranted for read-only
roles and the FK + profiling paths handle the empty PK map already.

* fix(llm): allow StructuredOutput tool and raise maxTurns for generateObject

The Claude Code agent SDK announces an internal pseudo-tool named
StructuredOutput in the system/init message whenever outputFormat is set
to { type: 'json_schema' }. The runtime's isolation check built its
allowedToolIds set only from MCP tool ids and treated StructuredOutput
as an unexpected host-injected tool, so every generateObject call threw
"Claude Code runtime isolation failed: tools=StructuredOutput ..." and
the table-descriptions and relationship-LLM-proposal enrichment stages
recorded null output across the board.

Whitelist StructuredOutput specifically in generateObject's
allowedToolIds — the check also enforces missing_tools symmetry, so
generateText and runAgentLoop, which do not see StructuredOutput, must
not require it.

generateObject also ran with maxTurns: 1, which the model intermittently
breached when it emitted thinking text before the structured response.
Raised to 5 to give the schema-bound call enough headroom without
allowing unbounded loops. The existing tests now exercise the path with
an init message that announces StructuredOutput so the regression cannot
slip back in.

* chore(scripts): add ktx-reset.sh project-cleanup helper

Convenience script for repeatable ingest testing: takes a project
directory and prunes everything except ktx.yaml and .ktx/secrets/, so
the next ktx setup or ktx ingest run starts from a known-clean state.

packages/cli/src/context/scan/enabled-tables.ts

@@ -1,17 +1,63 @@
-import type { KtxSchemaSnapshot } from './types.js';
+import { tableRefSet, type KtxTableRefKey } from './table-ref.js';
+import type { KtxTableRef } from './types.js';
 
-export function resolveEnabledTables(connection: Record<string, unknown> | undefined): Set<string> | null {
+/**
+ * Parses the `enabled_tables` field on a connection into a scope of
+ * fully-qualified table refs. Returns `null` when the field is absent or
+ * empty (meaning "no scope — include every table in the resolved schemas").
+ *
+ * Accepted entry forms:
+ *   "catalog.db.name"  — fully qualified
+ *   "db.name"          — schema-qualified (catalog = null; legacy / Postgres-shape)
+ *   "name"             — bare (catalog = db = null; SQLite-shape)
+ *   { catalog?, db?, name }  — escape hatch for identifiers containing dots
+ *
+ * The setup wizard writes the fully-qualified form going forward; the lenient
+ * parser keeps existing project configs working.
+ */
+export function resolveEnabledTables(
+  connection: Record<string, unknown> | undefined,
+): ReadonlySet<KtxTableRefKey> | null {
   const raw = connection?.enabled_tables;
   if (!Array.isArray(raw) || raw.length === 0) return null;
-  return new Set(raw.filter((v): v is string => typeof v === 'string'));
+  const refs: KtxTableRef[] = [];
+  for (const value of raw) {
+    const parsed = parseEnabledTableEntry(value);
+    if (parsed) refs.push(parsed);
+  }
+  if (refs.length === 0) return null;
+  return tableRefSet(refs);
 }
 
-export function filterSnapshotTables(snapshot: KtxSchemaSnapshot, enabledTables: Set<string>): KtxSchemaSnapshot {
-  return {
-    ...snapshot,
-    tables: snapshot.tables.filter((table) => {
-      const key = table.db ? `${table.db}.${table.name}` : table.name;
-      return enabledTables.has(key);
-    }),
-  };
+function parseEnabledTableEntry(value: unknown): KtxTableRef | null {
+  if (typeof value === 'string') {
+    return parseDottedEntry(value);
+  }
+  if (value && typeof value === 'object' && !Array.isArray(value)) {
+    const entry = value as { catalog?: unknown; db?: unknown; name?: unknown };
+    const name = typeof entry.name === 'string' ? entry.name : null;
+    if (!name) return null;
+    return {
+      catalog: typeof entry.catalog === 'string' ? entry.catalog : null,
+      db: typeof entry.db === 'string' ? entry.db : null,
+      name,
+    };
+  }
+  return null;
+}
+
+function parseDottedEntry(value: string): KtxTableRef | null {
+  const trimmed = value.trim();
+  if (trimmed.length === 0) return null;
+  const parts = trimmed.split('.');
+  if (parts.length === 3) {
+    return { catalog: parts[0]!, db: parts[1]!, name: parts[2]! };
+  }
+  if (parts.length === 2) {
+    return { catalog: null, db: parts[0]!, name: parts[1]! };
+  }
+  if (parts.length === 1) {
+    return { catalog: null, db: null, name: parts[0]! };
+  }
+  return null;
 }