ci: float opencode to latest in host-e2e instead of pinning 1.15.4

CI pinned opencode to a fixed version (1.15.4), so CI never ran the version
users actually run — which is exactly why opencode 1.16's post-overflow change
(commit 7e09660c3) wasn't caught when 1.16.0 shipped, only at our release time
when I had to downgrade locally to pass the gate. A gate that doesn't track the
real runtime can't catch upstream regressions.

Switch all five host-e2e opencode installs (ci.yml x2, release.yml x2,
smoke-opencode-linux.yml) from a hard "--version 1.15.4" pin to floating latest
(no --version flag). The original pin worked around a 1.15.5 linux-amd64
serve-startup hang; 1.16.x is the current line and the overflow-recovery test is
now version-agnostic, so the host suite passes on it (44/44 locally on 1.16.0).

Trade-off documented inline: a known-bad upstream opencode release can now turn
CI red for unrelated PRs — that's the correct signal (users would hit it too),
and the escape hatch is a temporary "--version X.Y.Z" re-pin until upstream
fixes it. SDK dep bump (@opencode-ai/* ^1.15.13 -> ^1.16.x) is deferred until the
3-day min-release-age gate clears on Jun 08 (all 1.16.x published Jun 05); not
blocking since the overflow change is in the opencode binary, not the SDK API.

Co-authored-by: Alfonso [Magic Context] <288211368+alfonso-magic-context@users.noreply.github.com>

Author: 2 people

.github/workflows/ci.yml

@@ -198,14 +198,16 @@ jobs:
       # Install opencode the same way the Docker image does — the host
       # suite spawns `opencode serve` from PATH.
       - name: Install opencode
-        # NOTE: pinned to 1.15.4 because opencode 1.15.5 on linux-amd64
-        # never responds to HTTP /doc after stdout reports "server listening",
-        # despite "Database migration complete." printing. waitForReady() in
-        # our test harness then times out at 5 min, killing every test in
-        # the suite. The same 1.15.5 binary works on macOS. Once a working
-        # newer release ships, drop the --version pin or move it up.
+        # Float to LATEST (no --version) so CI exercises the opencode version
+        # users actually run and catches upstream breakage as it ships — not at
+        # our release time. (A fixed pin previously hid opencode 1.16's
+        # post-overflow change, commit 7e09660c3, until release; the
+        # overflow-recovery host test is now version-agnostic.) Trade-off: a
+        # known-bad upstream release can turn CI red for unrelated PRs — if that
+        # happens, temporarily re-pin with `--version X.Y.Z` here until it's
+        # resolved upstream.
         run: |
-          curl -fsSL https://opencode.ai/install | bash -s -- --version 1.15.4
+          curl -fsSL https://opencode.ai/install | bash
           echo "$HOME/.opencode/bin" >> "$GITHUB_PATH"
 
       - name: Verify opencode on PATH
@@ -259,14 +261,11 @@ jobs:
 
       # pi-cross-harness.test.ts spawns BOTH a Pi runner and an OpenCode
       # serve to verify cross-harness memory sharing, so this job needs
-      # opencode on PATH too — same PINNED version the OpenCode host job uses.
-      # Pin to 1.15.4: opencode 1.15.5 on linux-amd64 never responds to HTTP
-      # /doc after stdout reports "server listening", so waitForReady() times
-      # out and the cross-harness test hangs (same hang the OpenCode host job
-      # pins around). Keep both jobs on the same version.
+      # opencode on PATH too. Float to LATEST like the OpenCode host job
+      # (see that step for the rationale + re-pin escape hatch).
       - name: Install opencode
         run: |
-          curl -fsSL https://opencode.ai/install | bash -s -- --version 1.15.4
+          curl -fsSL https://opencode.ai/install | bash
           echo "$HOME/.opencode/bin" >> "$GITHUB_PATH"
 
       - name: Verify opencode on PATH

.github/workflows/release.yml

@@ -212,11 +212,10 @@ jobs:
       # Install opencode the same way the Docker image does — the host
       # suite spawns `opencode serve` from PATH.
       - name: Install opencode
-        # NOTE: pinned to 1.15.4 because opencode 1.15.5 on linux-amd64
-        # never responds to HTTP /doc after stdout reports "server listening".
-        # See ci.yml for the same pin and details.
+        # Float to LATEST (the version users run). See ci.yml for the rationale
+        # + re-pin escape hatch for known-bad upstream builds.
         run: |
-          curl -fsSL https://opencode.ai/install | bash -s -- --version 1.15.4
+          curl -fsSL https://opencode.ai/install | bash
           echo "$HOME/.opencode/bin" >> "$GITHUB_PATH"
 
       - name: Verify opencode on PATH
@@ -263,14 +262,11 @@ jobs:
 
       # pi-cross-harness.test.ts spawns BOTH a Pi runner and an OpenCode
       # serve to verify cross-harness memory sharing, so this job needs
-      # opencode on PATH too — same PINNED version the OpenCode host job uses.
-      # Pin to 1.15.4: opencode 1.15.5 on linux-amd64 never responds to HTTP
-      # /doc after stdout reports "server listening", so waitForReady() times
-      # out and the cross-harness test hangs (same hang the OpenCode host job
-      # pins around). Keep both jobs on the same version.
+      # opencode on PATH too. Float to LATEST like the OpenCode host job
+      # (see ci.yml for the rationale + re-pin escape hatch).
       - name: Install opencode
         run: |
-          curl -fsSL https://opencode.ai/install | bash -s -- --version 1.15.4
+          curl -fsSL https://opencode.ai/install | bash
           echo "$HOME/.opencode/bin" >> "$GITHUB_PATH"
 
       - name: Verify opencode on PATH

.github/workflows/smoke-opencode-linux.yml

@@ -49,9 +49,12 @@ jobs:
         with:
           bun-version: latest
 
-      - name: Install opencode (1.15.4 pin matches host e2e)
+      - name: Install opencode (latest — matches host e2e)
+        # Float to latest: this smoke job exists to catch a Linux serve-startup
+        # regression, so it must run the version users get. See ci.yml host job
+        # for the re-pin escape hatch if an upstream build is known-bad.
         run: |
-          curl -fsSL https://opencode.ai/install | bash -s -- --version 1.15.4
+          curl -fsSL https://opencode.ai/install | bash
           echo "$HOME/.opencode/bin" >> "$GITHUB_PATH"
 
       - name: Verify opencode binary