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/integration/collaboration-flow.test.ts

@@ -106,12 +106,15 @@ describe("collaboration integration flow", () => {
 
     const state = snapshot.load();
     const evalRun = state.evalRuns.find((run) => run.id === evalRunId);
-    const snapshotRecord = state.skillRuntimeSnapshots[0];
+    // Compiled runtime snapshots live in the database only - the renderer
+    // snapshot must not carry per-run compiled prompts.
+    const snapshotRecord = connection.db.prepare("select compiled_prompt from skill_runtime_snapshots limit 1")
+      .get() as { compiled_prompt: string } | undefined;
     if (!evalRun) throw new Error("Integration eval run was not created.");
     if (!snapshotRecord) throw new Error("Skill runtime snapshot was not created.");
     expect(state.approvals.find((approval) => approval.id === approvalId)?.state).toBe(APPROVAL_STATE.APPROVED);
     expect(state.approvalAssignments.some((assignment) => assignment.approvalId === approvalId)).toBe(true);
-    expect(snapshotRecord.compiledPrompt).toContain("Release Gate");
+    expect(snapshotRecord.compiled_prompt).toContain("Release Gate");
     expect(evalRun).toMatchObject({ state: SDLC_RUN_STATE.PASSED, failedCount: 0 });
     expect(state.operationalEvents.some((event) => event.signalKey === "skill_resolve_success")).toBe(true);
     connection.close();