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/relationship-profiling.test.ts

@@ -1,7 +1,7 @@
 import { readFile } from 'node:fs/promises';
 import { join } from 'node:path';
 import Database from 'better-sqlite3';
-import { afterEach, describe, expect, it } from 'vitest';
+import { afterEach, describe, expect, it, vi } from 'vitest';
 import type { KtxEnrichedColumn, KtxEnrichedSchema, KtxEnrichedTable } from './enrichment-types.js';
 import { snapshotToKtxEnrichedSchema } from './local-enrichment.js';
 import { loadKtxRelationshipBenchmarkFixture, maskKtxRelationshipBenchmarkSnapshot } from './relationship-benchmarks.js';
@@ -351,4 +351,94 @@ describe('relationship profiling', () => {
       scaleExecutor.close();
     }
   });
+
+  it('profiles tables concurrently up to profileConcurrency', async () => {
+    let inFlight = 0;
+    let maxInFlight = 0;
+    const executor = {
+      executeReadOnly: vi.fn(async (input: KtxReadOnlyQueryInput) => {
+        inFlight += 1;
+        maxInFlight = Math.max(maxInFlight, inFlight);
+        await new Promise((resolve) => setTimeout(resolve, 10));
+        inFlight -= 1;
+        return {
+          headers: [
+            'column_name',
+            'table_row_count',
+            'row_count',
+            'null_count',
+            'distinct_count',
+            'min_text_length',
+            'max_text_length',
+            'sample_values',
+          ],
+          rows: [[input.sql.includes('accounts') ? 'id' : 'account_id', 2, 2, 0, 2, 1, 2, '1\u001f2']],
+          totalRows: 1,
+          rowCount: 1,
+        };
+      }),
+    };
+
+    await profileKtxRelationshipSchema({
+      connectionId: 'warehouse',
+      driver: 'sqlite',
+      schema: schemaWithTables(['accounts', 'orders', 'payments', 'refunds']),
+      executor,
+      ctx: { runId: 'profile-concurrency' },
+      profileConcurrency: 4,
+    });
+
+    expect(maxInFlight).toBe(4);
+  });
+
+  it('keeps profiling other tables when one table profile fails', async () => {
+    const executor = {
+      executeReadOnly: vi.fn(async (input: KtxReadOnlyQueryInput) => {
+        if (input.sql.includes('"orders"')) {
+          throw new Error('orders unavailable');
+        }
+        return {
+          headers: [
+            'column_name',
+            'table_row_count',
+            'row_count',
+            'null_count',
+            'distinct_count',
+            'min_text_length',
+            'max_text_length',
+            'sample_values',
+          ],
+          rows: [['id', 2, 2, 0, 2, 1, 2, '1\u001f2']],
+          totalRows: 1,
+          rowCount: 1,
+        };
+      }),
+    };
+
+    const result = await profileKtxRelationshipSchema({
+      connectionId: 'warehouse',
+      driver: 'sqlite',
+      schema: schemaWithTables(['accounts', 'orders']),
+      executor,
+      ctx: { runId: 'profile-error-isolated' },
+      profileConcurrency: 2,
+    });
+
+    expect(result.warnings).toContain('profile_failed:orders:orders unavailable');
+    expect(result.tables).toHaveLength(2);
+    expect(Object.keys(result.columns)).toContain('accounts.id');
+  });
 });
+
+function schemaWithTables(names: string[]): KtxEnrichedSchema {
+  return schema(
+    names.map((name) =>
+      table(name, [
+        column(name, name === 'orders' ? 'account_id' : 'id', {
+          nullable: false,
+          primaryKey: name !== 'orders',
+        }),
+      ]),
+    ),
+  );
+}