fix(compile): detect and prevent workspace checkout collision with self repo

[Copilot]

Summary

When a workspace:/checkout: entry references the same ADO repo checked out as self, both checkouts land in s/<repo-name> and the second silently overwrites the first — wiping files that exist only on the trigger branch and breaking downstream steps like the integrity check.

Changes in src/compile/common.rs:

• New validate_checkout_self_collision() validator — compares the trailing path segment of each repositories: entry's name: against the trigger repo's Build.Repository.Name (case-insensitive, so the collision is caught regardless of agent OS) and fails compilation with a message naming both repos.
• Wired into compile_shared() immediately after validate_front_matter_identity(), using ctx.ado_context.repo_name. Skipped when no ADO remote is inferable (unit tests, non-ADO clones).
• Unit tests for collision, no collision, case-insensitive match, missing self name (skipped), and empty checkout.

Example error:

Checkout entry 'my-repo' (repository name 'some-org/my-repo') resolves to the
same directory ('s/my-repo') as the trigger repository checked out as 'self'.
The second checkout would overwrite the first... Remove 'my-repo' from
'checkout:' — the 'self' checkout already provides access to this repository.

Test plan

• cargo test — 5 new unit tests pass; full suite (1225 lib + integration) green.
• cargo clippy --all-targets --all-features — clean.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• spsprodeus21.vssps.visualstudio.com
  • Triggering command: /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 6ksh238exvmortfjlrt.10a8z9q.rcgu.o tbxwvryn5xpq24sz29i.10a8z9q.rcgu.o 3yom1iovwt5ppeyg0wz.10a8z9q.rcgu.o w6z6s1vrexzyhlxi46w.10a8z9q.rcgu.o lxmz0i1607yew7j1rhw.10a8z9q.rcgu.o w1m2uyz3quhc8lugxeo.10a8z9q.rcgu.o jj3q0h3xzhc5zw4ox4i.10a8z9q.rcgu.o wnqg94hqb3cq8knkly5.10a8z9q.rcgu.o 9nv177l742jj24fbqcw.10a8z9q.rcgu.o j1mz2tzr9lnn7p4kdm5.10a8z9q.rcgu.o nzrfoj06d04urrsfl5u.10a8z9q.rcgu.o wu9y�� vzu1tytj0tvhb4hmwaq.10a8z9q.rcgu.o sqbxfafyavajksk78r4.10a8z9q.rcgu.o f/fuzzy-matcher---crate-type lib/rustlib/x86_tail lib/rustlib/x86_-30 lib/rustlib/x86_-C lib/rustlib/x86_embed-bitcode=no (dns block)
  • Triggering command: /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 s/compiler_testsremote s/compiler_testsget-url s/compiler_testsorigin s/co�� s/compiler_tests-404504f8280230b7.220tvu26dzce9gekbyb7ksyvt.0x6vv29.rcgu.o s/compiler_tests-404504f8280230b7.23v7xa4xymljcg9ofrfxmw64p.0x6vv29.rcgu.o s/compiler_tests-404504f8280230b7.2appb879eywzbt0j76y0j34nd.0x6vv29.rcgu.o s/compiler_testsgit s/compiler_testsremote s/compiler_testsget-url s/compiler_testsorigin s/co�� gent.md s/compiler_tests-404504f8280230b7.34l7hzdvh2gso9fueo8gvjk9c.0x6vv29.rcgu.o 0063-18/pr-filter-tier1-agent.yml target/debug/depgit target/debug/depremote target/debug/depget-url i-7aeefe72516b1eorigin (dns block)
• spsprodweu4.vssps.visualstudio.com
  • Triggering command: /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 6ksh238exvmortfjlrt.10a8z9q.rcgu.o tbxwvryn5xpq24sz29i.10a8z9q.rcgu.o 3yom1iovwt5ppeyg0wz.10a8z9q.rcgu.o w6z6s1vrexzyhlxi46w.10a8z9q.rcgu.o lxmz0i1607yew7j1rhw.10a8z9q.rcgu.o w1m2uyz3quhc8lugxeo.10a8z9q.rcgu.o jj3q0h3xzhc5zw4ox4i.10a8z9q.rcgu.o wnqg94hqb3cq8knkly5.10a8z9q.rcgu.o 9nv177l742jj24fbqcw.10a8z9q.rcgu.o j1mz2tzr9lnn7p4kdm5.10a8z9q.rcgu.o nzrfoj06d04urrsfl5u.10a8z9q.rcgu.o wu9y�� vzu1tytj0tvhb4hmwaq.10a8z9q.rcgu.o sqbxfafyavajksk78r4.10a8z9q.rcgu.o f/fuzzy-matcher---crate-type lib/rustlib/x86_tail lib/rustlib/x86_-30 lib/rustlib/x86_-C lib/rustlib/x86_embed-bitcode=no (dns block)
  • Triggering command: /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 /home/REDACTED/work/ado-aw/ado-aw/target/debug/deps/ado_aw-a3f02ec5a93c8182 s/compiler_testsremote s/compiler_testsget-url s/compiler_testsorigin s/co�� s/compiler_tests-404504f8280230b7.220tvu26dzce9gekbyb7ksyvt.0x6vv29.rcgu.o s/compiler_tests-404504f8280230b7.23v7xa4xymljcg9ofrfxmw64p.0x6vv29.rcgu.o s/compiler_tests-404504f8280230b7.2appb879eywzbt0j76y0j34nd.0x6vv29.rcgu.o s/compiler_testsgit s/compiler_testsremote s/compiler_testsget-url s/compiler_testsorigin s/co�� gent.md s/compiler_tests-404504f8280230b7.34l7hzdvh2gso9fueo8gvjk9c.0x6vv29.rcgu.o 0063-18/pr-filter-tier1-agent.yml target/debug/depgit target/debug/depremote target/debug/depget-url i-7aeefe72516b1eorigin (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)