Make workspace authoring converge through immutable Nix candidates

Coordinate registered resource edits bottom-up into retained exact remote sources.
Use one Nix-owned source graph for provisional checking, template publication,
explicit baseline upgrades and host activation; retain independent runtime pins.

Add scoped contract inspection, historical recovery, derived worklists, crash-safe
locks, named dependency adoption and plain-QX structural editing. Repair TODO
ownership and template instantiation, and document the supported agent workflow.

Validated with protocol and command suites, real jj/Nix convergence and cache
checks, TS/React installed-command acceptance, and fresh TODO first-edit acceptance.
No live deployment or public publication performed. Props projection generation
and a one-command rich feature generator remain explicitly outside this delivery.

test/pin-upgrades.test.ts

@@ -8,13 +8,14 @@ import {execFile as callback} from "node:child_process";
 import {planPinUpgrades, applyPinUpgrades, type UpgradeEffects} from "../src/capability-language/pin-upgrades.js";
 const execFile = promisify(callback);
 
-test("real jj snapshots and immutable Git publication propagate a changed interface into the root", async (context) => {
+test("real jj snapshots and immutable Git publication propagate a changed interface into the root", {skip: !process.env.QX_CHECK_GENERATOR}, async (context) => {
   const workbench = await fs.mkdtemp(path.join(os.tmpdir(), "qx-real-upgrade-"));
   context.after(() => fs.rm(workbench, {recursive: true, force: true}));
   // Exercise the actual effects with local bare remotes, without external writes.
   const environment = {
     GIT_CONFIG_COUNT: "1", GIT_CONFIG_KEY_0: `url.file://${workbench}/remotes/.insteadOf`,
     GIT_CONFIG_VALUE_0: "https://upgrade.test/", QUIXOS_JJ_NO_CHECKPOINT: "1",
+    QUIXOS_CHECK_GENERATOR: process.env.QX_CHECK_GENERATOR!,
   };
   const previous = Object.fromEntries(Object.keys(environment).map(key => [key, process.env[key]]));
   Object.assign(process.env, environment);