fix(android): restore monotonic versionCode and guard releases (v0.9.17 = uninstallable)

[dannymcc]

Problem

Installing the v0.9.17 release fails on-device with a bare "App not installed" dialog. It isn't a signing issue — every official release is signed with the same keystore from CI secrets. It's a versionCode downgrade.

Actual values baked into the shipped APKs:

Release	versionCode	versionName
v0.9.15	48	0.9.15
v0.9.16	48	0.9.15
v0.9.17	1	0.9.17

android/app/build.gradle.kts sets versionCode = flutter.versionCode, and Flutter derives that from the +BUILD suffix in pubspec.yaml. Commit c8d75af set version: 0.9.17+1, so versionCode collapsed 48 → 1. Android refuses to install an APK whose versionCode is lower than the installed one (INSTALL_FAILED_VERSION_DOWNGRADE), shown to users as "App not installed".

(Two supporting clues: v0.9.16 is byte-for-byte identical to v0.9.15 and still reports versionName 0.9.15 — pubspec wasn't bumped for that tag either; and the release trigger is just push: tags: ['v*'], so a bad pubspec sails straight to a published release with no gate.)

Fix

1. pubspec.yaml → 0.9.18+49 — restores a monotonic versionCode (49 > 48). A fresh patch release rather than re-cutting the burned v0.9.17 tag; 49 upgrades cleanly over both the versionCode-48 installs and anyone who grabbed the broken versionCode-1 build.

2. Release-time CI guard in build.yml (runs before the build) that fails the release when the versionCode is:

   • missing the +BUILD suffix (the exact v0.9.17 footgun — Flutter would silently fall back to 1),
   • non-integer,
   • mismatched with the release tag's versionName, or
   • not strictly greater than the highest already-released versionCode.

   Needs fetch-depth: 0 on checkout so it can read prior tags' pubspec. Verified locally: passes for 0.9.18+49, and correctly rejects the 0.9.17+1 case (versionCode 1 <= prior max 48).

Note for release cutter

v0.9.17 is already published with versionCode 1 and can't be fixed in place — cut v0.9.18 from this branch once merged. Anyone who installed the broken v0.9.17 will be able to upgrade to v0.9.18 normally.

Heads-up from the pubspec comment: a version bump also needs the iOS MARKETING_VERSION/CURRENT_PROJECT_VERSION updated for the widget/watch targets in project.pbxproj. Left out of this PR to keep it Android-focused — flag if you'd like it folded in.

Summary by CodeRabbit

• New Features

  • Added release validation to ensure Android version numbers match release tags and increase consistently.
  • Releases now stop early when version information is missing, invalid, mismatched, or not higher than previous releases.

• Chores

  • Updated the app version to 0.9.18 (build 49).

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 56dbe96c-05e2-4b0a-85ad-e3d3bb77b004

📥 Commits

Reviewing files that changed from the base of the PR and between c8d75af and 95dc41d.

📒 Files selected for processing (2)

• .github/workflows/build.yml
• pubspec.yaml

---

📝 Walkthrough

Walkthrough

The package version is bumped to 0.9.18+49. The Android release workflow adds a pre-build guard that validates the build suffix, release tag, and strict versionCode increase across prior v* tags.

Changes

Release version validation

Layer / File(s)	Summary
Version bump and release guard .github/workflows/build.yml, pubspec.yaml	The package version changes to 0.9.18+49, and the Android workflow validates its integer build suffix, tag correspondence, and versionCode against prior v* tags before building.

Estimated code review effort: 3 (Moderate) | ~15–30 minutes

Suggested reviewers: abdulsaheel

Sequence Diagram(s)

sequenceDiagram
  participant Workflow as Android release workflow
  participant Pubspec as pubspec.yaml
  participant Tags as prior v* git tags
  Workflow->>Pubspec: Read package version
  Workflow->>Tags: Read prior versionCode values
  Workflow->>Workflow: Validate tag match and increasing versionCode
  Workflow->>Workflow: Continue build when checks pass

Loading

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the Android versionCode fix and new release guard, matching the main changes in the PR.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

_{Comment @coderabbitai help to get the list of available commands.}