feat(platform): add setAssignee() to PlatformAdapter (GitHub + ADO)

[babonet]

Closes part of the ADO-first squad routing gap. Adds setAssignee() to PlatformAdapter so assignee changes route through the platform abstraction instead of inline gh/az branches.

• GitHubAdapter: gh issue edit --add/--remove-assignee
• AzureDevOpsAdapter: System.AssignedTo
• watch editWorkItem delegates to adapter (removes hardcoded gh-vs-ado branch)
• tests + changeset (sdk minor, cli patch)

Validation: SKIP_BUILD_BUMP=1 npm run build; vitest platform (135 pass).

[github-actions]

🟡 Impact Analysis — PR #1413

Risk tier: 🟡 MEDIUM

📊 Summary

Metric	Count
Files changed	7
Files added	1
Files modified	6
Files deleted	0
Modules touched	4
Critical files	1

🎯 Risk Factors

• 7 files changed (6-20 → MEDIUM)
• 4 modules touched (2-4 → MEDIUM)
• Critical files touched: packages/squad-cli/src/cli/commands/watch/index.ts

📦 Modules Affected

root (1 file)

• .changeset/forge-set-assignee.md

squad-cli (2 files)

• packages/squad-cli/src/cli/commands/loop.ts
• packages/squad-cli/src/cli/commands/watch/index.ts

squad-sdk (3 files)

• packages/squad-sdk/src/platform/azure-devops.ts
• packages/squad-sdk/src/platform/github.ts
• packages/squad-sdk/src/platform/types.ts

tests (1 file)

• test/platform-adapter.test.ts

⚠️ Critical Files

• packages/squad-cli/src/cli/commands/watch/index.ts

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This report is generated automatically for every PR. See #733 for details.

[github-actions]

🛫 PR Readiness Check

ℹ️ This comment updates on each push. Last checked: commit 969886a

PR Scope: 📦🔧 Mixed (product + infrastructure)

⚠️ 2 item(s) to address before review

Status	Check	Details
✅	Single commit	1 commit — clean history
✅	Not in draft	Ready for review
✅	Branch up to date	Up to date with dev
❌	Copilot review	No Copilot review yet — it may still be processing
✅	Changeset present	Changeset file found
✅	Scope clean	No .squad/ or docs/proposals/ files
✅	No merge conflicts	No merge conflicts
✅	Copilot threads resolved	0 active Copilot thread(s) resolved (4 outdated skipped)
❌	CI passing	4 check(s) still running

Files Changed (7 files, +214 −156)

File	+/−
.changeset/forge-set-assignee.md	+8 −0
packages/squad-cli/src/cli/commands/loop.ts	+1 −0
packages/squad-cli/src/cli/commands/watch/index.ts	+10 −18
packages/squad-sdk/src/platform/azure-devops.ts	+11 −0
packages/squad-sdk/src/platform/github.ts	+13 −0
packages/squad-sdk/src/platform/types.ts	+5 −0
test/platform-adapter.test.ts	+166 −138

Total: +214 −156

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This check runs automatically on every push. Fix any ❌ items and push again.
See CONTRIBUTING.md and PR Requirements for details.

[Copilot]

Pull request overview

Adds a setAssignee() operation to the PlatformAdapter so assignee changes can be routed through the platform abstraction (GitHub + Azure DevOps) instead of being implemented as inline gh/az branches in CLI code.

Changes:

• Extends PlatformAdapter with setAssignee(workItemId, assignee) and wires implementations for GitHub and Azure DevOps.
• Updates the watch command’s editWorkItem to delegate assignee changes to the adapter.
• Adds test coverage for the interface shape and includes a changeset bump (SDK minor, CLI patch).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
packages/squad-sdk/src/platform/types.ts	Adds setAssignee() to the platform adapter contract and documents expected behavior.
packages/squad-sdk/src/platform/github.ts	Implements GitHubAdapter.setAssignee() via gh issue edit.
packages/squad-sdk/src/platform/azure-devops.ts	Implements AzureDevOpsAdapter.setAssignee() via System.AssignedTo.
packages/squad-cli/src/cli/commands/watch/index.ts	Replaces inline platform branching with adapter.setAssignee() calls.
packages/squad-cli/src/cli/commands/loop.ts	Updates the noop adapter to satisfy the new interface.
test/platform-adapter.test.ts	Updates interface conformance mocks and adds a basic interface-shape test for setAssignee.
.changeset/forge-set-assignee.md	Records version bumps and describes the new adapter capability.

[babonet]

Addressed all four review comments in the latest push (969886a):

1. github.ts unassign — undefined now fetches the current assignee and removes the right user instead of always removing @me.
2. ADO @me — setAssignee('@me') is now a no-op (matches prior best-effort behavior; no accidental unassign in executeIssue).
3. watch removeAssignee — retyped as boolean flag; unassign clears current assignee on both platforms.
4. types.ts doc — clarified @me assigns current user on GitHub only; ADO skips it.

Build green, 134 platform tests pass.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated no new comments.

[tamirdresher]

✅ Approved — clean platform abstraction for setAssignee(). Security review: no new injection vectors (array-based exec, not shell). The TOCTOU race on unassign is harmless (best-effort with try/catch). removeAssignee type change from string→boolean is correct and internal-only. ADO @me no-op is documented and matches prior behavior. Tests cover the contract. Ship it.

[tamirdresher]

Thanks Oren! Clean work on the platform abstraction. 🙌