Stop shipping megabytes of skill prompts in every snapshot refresh

The whole app turned to molasses because snapshot.load() shipped the
entire skill_runtime_snapshots table - unbounded, compiled_prompt
included - over IPC on every refresh. A real profile carried 142 rows
totaling 144MB (1.1MB each from the pre-cap CEO compile-all era), so
every coalesced refresh serialized ~144MB of JSON. The forced-humanizer
rework made it worse by adding a row per run for every agent.

- Drop skillRuntimeSnapshots, skillRevisions, skillTests, and
  skillBindings from the renderer snapshot: no renderer surface reads
  them; skill internals are main-process state. Only the lightweight
  skillDefinitions catalogue still ships.
- Project provider_requests without raw_response_json (4.1MB across the
  newest 100 rows; RunsPage only reads responseText)
- Migration 051 purges the bug-era compiled prompts from existing DBs
- resolveRuntimeSnapshot is now idempotent per run: a run re-queued by
  startup recovery reuses its frozen snapshot instead of dying on the
  uniqueness guard and burning real retry budget
- Regression test pins the contract: a 2MB database row must not add
  bytes to the snapshot (payload asserted under 400KB)

tests/unit/snapshot-payload.test.ts

@@ -0,0 +1,49 @@
+import { randomUUID } from "node:crypto";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { describe, expect, test } from "vitest";
+import { DatabaseConnection } from "../../src/main/database/connection";
+import { OrganizationService } from "../../src/main/services/organization-service";
+import { SnapshotService } from "../../src/main/services/snapshot-service";
+
+/**
+ * The snapshot is serialized over IPC on every refresh, so its size is a
+ * user-facing performance contract. A real profile once accumulated 144MB of
+ * per-run compiled skill prompts that rode along on every load and froze the
+ * whole app - these tests pin that regression class shut.
+ */
+describe("snapshot payload", () => {
+  test("per-run compiled prompts and raw provider bodies never ride the snapshot", () => {
+    const connection = new DatabaseConnection(join(tmpdir(), `ac-snapshot-payload-${randomUUID()}.db`));
+    const organization = new OrganizationService(connection.db);
+    const snapshot = new SnapshotService(connection.db);
+    let orgId = "";
+    connection.transaction(() => {
+      orgId = organization.createOrganization({ organizationName: "OrbitOps", employeeName: "Yang", mission: "m", goal: "g" });
+      const agentId = organization.createAgent({
+        orgId, name: "Ada", role: "Engineer", department: "Engineering",
+        modelProviderId: null, modelId: null, budgetCents: 1000, managerAgentId: null,
+      });
+      const providerId = (connection.db.prepare("select id from providers where org_id = ? limit 1").get(orgId) as { id: string }).id;
+      const megabyte = "x".repeat(1_048_576);
+      connection.db.prepare(`
+        insert into skill_runtime_snapshots(id, agent_id, run_id, compiled_prompt, tools_manifest, source_revision_ids, created_at)
+        values ('srs_fat', ?, 'run_fat', ?, '{}', '[]', ?)
+      `).run(agentId, megabyte, new Date().toISOString());
+      connection.db.prepare(`
+        insert into provider_requests(id, org_id, provider_id, provider_key, model, prompt_sha256, response_text, raw_response_json, state, error_message, created_at, completed_at)
+        values ('prq_fat', ?, ?, 'openai', 'gpt-5.4', 'sha', 'short answer', ?, 'succeeded', null, ?, ?)
+      `).run(orgId, providerId, megabyte, new Date().toISOString(), new Date().toISOString());
+    });
+
+    const state = snapshot.load();
+    expect(state).not.toHaveProperty("skillRuntimeSnapshots");
+    expect(state).not.toHaveProperty("skillRevisions");
+    const request = state.providerRequests.find((row) => row.id === "prq_fat");
+    expect(request?.responseText).toBe("short answer");
+    expect(request).not.toHaveProperty("rawResponseJson");
+    // Two megabytes of database bloat must not translate into snapshot bytes.
+    expect(JSON.stringify(state).length).toBeLessThan(400_000);
+    connection.close();
+  });
+});