diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index daa8826c..e7fd4465 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,7 +13,12 @@ jobs:
       - run: pnpm install --frozen-lockfile
       - run: pnpm -r run build
       - run: pnpm -r run typecheck
-      - run: pnpm -r run test   # amico-run suite (incl. S31 grep rule) + extension unit suite + @amicode/schema conformance
+      # Fetch the vendored opencode BEFORE vitest so the OC_BIN-gated integration
+      # test (opencode config injection + merge) actually RUNS in CI instead of
+      # self-skipping — the skip was the #25 CI-level false-green (an injection or
+      # config-merge regression would pass CI because the only test for it skipped).
+      - run: pnpm --filter amicode-v2 fetch:opencode
+      - run: pnpm -r run test   # amico-run suite (incl. S31 grep rule) + extension unit suite (incl. the opencode inject/merge integration) + @amicode/schema conformance
       - name: amico-validate — shipped configs conform + linked bin works (0.1c gate)
         run: |
           # Exercise the LINKED bin via a dependent (the bin links into amico-run /
diff --git a/packages/extension/test/boot_smoke.mjs b/packages/extension/test/boot_smoke.mjs
index e295fbbd..d5d461d2 100644
--- a/packages/extension/test/boot_smoke.mjs
+++ b/packages/extension/test/boot_smoke.mjs
@@ -3,6 +3,14 @@
 // GET /event as an SSE stream (HTTP 200, text/event-stream) against a
 // synthesized project, with no LLM creds. Exit 0 = pass.
 //
+// SCOPE (see #25): this is the binary-liveness gate only — it deliberately does
+// NOT set OPENCODE_CONFIG_CONTENT, so it can't (and doesn't claim to) catch a
+// regression in the instructions/permission injection or the config merge. That
+// injection + merge is asserted against the REAL binary + the REAL
+// buildOpencodeConfigContent in test/opencode_config.test.ts ("opencode config
+// injection + merge"), which can import the TS builder (this .mjs can't, so
+// re-deriving the config here would just risk drift).
+//
 // Boot + probe logic lives in scripts/opencode_probe.mjs (shared with the
 // healthcheck, which derives BOTH the /event gate and the provider signal from a
 // single boot); this script asserts the /event gate and exits.
diff --git a/packages/extension/test/opencode_config.test.ts b/packages/extension/test/opencode_config.test.ts
index 1d572012..9620d58d 100644
--- a/packages/extension/test/opencode_config.test.ts
+++ b/packages/extension/test/opencode_config.test.ts
@@ -66,25 +66,44 @@ describe('buildOpencodeConfigContent', () => {
   })
 })
 
-// Integration: confirms opencode 1.17.3 DEEP-merges the injected `permission`
-// object over the user's global config rather than shallow-replacing it (which
-// would wipe the user's other permission keys). Skipped when the vendored binary
-// isn't present (e.g. minimal CI before `fetch:opencode`).
+// Integration (#25): boots the REAL opencode binary (`opencode debug config`
+// resolves + dumps the merged config, equivalent to GET /config) with the REAL
+// buildOpencodeConfigContent as OPENCODE_CONFIG_CONTENT, and asserts the whole
+// injection + merge the extension relies on at spawn:
+//   - the injected `instructions` (the AGENTS.md path) is present — this is the
+//     regression the old boot_smoke false-green missed: boot_smoke.mjs boots
+//     WITHOUT OPENCODE_CONFIG_CONTENT, so it stayed green even if the instruction
+//     injection were removed. This test reds instead.
+//   - the user's global `model` survives the deep-merge (opencode picks the
+//     provider from it — the merge must not clobber it);
+//   - the user's global `permission` keys survive AND our injected permission key
+//     is added (deep-merge, not shallow-replace — folds in the #22 check).
+// Uses the real builder (no transcribed copy → no drift; boot_smoke.mjs can't
+// import the TS builder, which is why this lives here). Skipped when the vendored
+// binary isn't present (e.g. minimal CI before `fetch:opencode`).
 const OC_BIN = join(__dirname, '..', 'vendor', 'opencode', `${process.platform}-${process.arch}`, 'opencode')
-describe.skipIf(!existsSync(OC_BIN))('opencode permission merge (1.17.3)', () => {
-  it('injected permission ADDS keys — the user\'s global permission keys survive', () => {
+describe.skipIf(!existsSync(OC_BIN))('opencode config injection + merge (1.17.3)', () => {
+  it('injects instructions/permission AND preserves the user global model + permission', () => {
     const home = mkdtempSync(join(tmpdir(), 'ochome-'))
     mkdirSync(join(home, '.config', 'opencode'), { recursive: true })
+    // A user global config with a distinctive model + permission key — both must
+    // survive the deep-merge under OPENCODE_CONFIG_CONTENT.
     writeFileSync(join(home, '.config', 'opencode', 'opencode.json'),
-      JSON.stringify({ permission: { doom_loop: 'deny' } }))   // a distinctive user-set key
+      JSON.stringify({ model: 'anthropic/claude-sonnet-4-6', permission: { doom_loop: 'deny' } }))
+    const agentsPath = join(home, 'AGENTS.md')   // the exact file our `instructions` must point at
+    writeFileSync(agentsPath, '# amico\n')
     const out = execFileSync(OC_BIN, ['debug', 'config'], {
       encoding: 'utf8',
       env: { ...process.env, HOME: home, XDG_CONFIG_HOME: join(home, '.config'),
-             OPENCODE_CONFIG_CONTENT: buildOpencodeConfigContent('/abs/AGENTS.md', '/ext/templates/solve_template.jl') },
+             OPENCODE_CONFIG_CONTENT: buildOpencodeConfigContent(agentsPath, '/ext/templates/solve_template.jl') },
     })
     const cfg = JSON.parse(out)
-    expect(cfg.permission.doom_loop).toBe('deny')                   // user's key SURVIVED the deep-merge
-    expect(typeof cfg.permission.external_directory).toBe('object') // our injected key is present too
+    // our injection landed (the false-green boot_smoke couldn't catch):
+    expect(cfg.instructions).toContain(agentsPath)                 // the AGENTS.md instruction injection
+    expect(typeof cfg.permission.external_directory).toBe('object') // our injected permission key
+    // the user's global config SURVIVED the deep-merge:
+    expect(cfg.model).toBe('anthropic/claude-sonnet-4-6')          // provider/model preserved (Q129 needs this)
+    expect(cfg.permission.doom_loop).toBe('deny')                  // user permission key preserved (#22)
   })
 })