feat(bin): detect a real Chromium binary in bootstrap

[Freudator86]

Intent

Add real Chromium binary detection to bin/fm-bootstrap.sh's tool-detection machinery. Chromium was documented (chromium-toolchain-r7k, PR #704) as a required toolchain item for chrome-devtools-axi's headless launches but bootstrap never actually checked for it. Added a chromium_binary_present() helper that checks candidate binary names (chromium, chromium-browser, google-chrome, google-chrome-stable) since no single name is universal across install methods (system package vs Playwright-managed install), wired into the existing install_cmd/MISSING: reporting convention used by every other tool in the script (install command is 'npx --yes playwright install-deps chromium', matching the doc PR's documented manual remediation). This is a fleet-wide framework change scoped only to the detection gap - it deliberately does not touch docs/configuration.md, which is owned by the separate still-open PR #704. Extended tests/fm-bootstrap.test.sh with a new test_chromium_binary_detection covering missing, present, and each alternate binary name, and stubbed a fake chromium binary into the shared make_fake_toolchain fixture so existing silent-output test cases remain silent. Ran bin/fm-lint.sh (shellcheck 0.11.0) clean before committing.

What Changed

• Added a chromium_binary_present() helper to bin/fm-bootstrap.sh that checks for any of chromium, chromium-browser, google-chrome, or google-chrome-stable on PATH, since no single binary name is universal across install methods (system package vs. Playwright-managed install).
• Wired the check into the existing install_cmd/MISSING: reporting convention, emitting MISSING: chromium (install: npx --yes playwright install-deps chromium) when no candidate binary is found.
• Extended tests/fm-bootstrap.test.sh with test_chromium_binary_detection, covering the missing case, the present case, and each alternate binary name, and stubbed a fake chromium binary into the shared make_fake_toolchain fixture so existing silent-output test cases remain silent.

Risk Assessment

✅ Low: Small, well-bounded addition (one detection helper + one MISSING line + matching tests) that follows the script's existing install_cmd/MISSING conventions, is unconditional in a way consistent with chrome-devtools-axi already being a universal COMMON_TOOLS entry, and matches every constraint in the stated intent (candidate names, install command, non-touching of docs/configuration.md, test fixture updates).

Testing

Ran the full fm-bootstrap test suite (22/22 pass, including the new test_chromium_binary_detection covering missing/present/alternate-name cases), then independently reproduced the end-user CLI experience by invoking bin/fm-bootstrap.sh directly with a fake toolchain: with no Chromium-family binary on PATH it prints MISSING: chromium with the documented playwright install command, and adding a chromium-browser stub makes that line disappear while other MISSING lines stay unaffected — confirming the detection helper and its wiring into the MISSING: reporting convention work end-to-end as the author intended.

Evidence: Manual CLI transcript: bootstrap output with/without a chromium-family binary on PATH

=== Scenario A: no chromium binary on PATH ===
MISSING: treehouse (install: curl -fsSL https://kunchenguid.github.io/treehouse/install.sh | sh)
MISSING: no-mistakes (install: curl -fsSL https://raw.githubusercontent.com/kunchenguid/no-mistakes/main/docs/install.sh | sh)
MISSING: tasks-axi (install: npm install -g tasks-axi)
MISSING: quota-axi (install: npm install -g quota-axi)
MISSING: chromium (install: npx --yes playwright install-deps chromium)

=== Scenario B: a real-shaped chromium-browser binary added to PATH ===
MISSING: treehouse (install: curl -fsSL https://kunchenguid.github.io/treehouse/install.sh | sh)
MISSING: no-mistakes (install: curl -fsSL https://raw.githubusercontent.com/kunchenguid/no-mistakes/main/docs/install.sh | sh)
MISSING: tasks-axi (install: npm install -g tasks-axi)
MISSING: quota-axi (install: npm install -g quota-axi)

Pipeline

Updates from git push no-mistakes

✅ **intent** - passed

✅ No issues found.

✅ **Rebase** - passed

✅ No issues found.

⚠️ **Review** - 1 info

• ℹ️ bin/fm-bootstrap.sh:8 - The file header comment documents every special-cased MISSING behavior (treehouse's lease-support check, no-mistakes' version check, tasks-axi/quota-axi's version+feature gate) but wasn't updated to mention the new unconditional 'MISSING: chromium' check, which is likewise a bespoke check outside the COMMON_TOOLS/BACKEND_TOOLS loop. Worth a one-line addition alongside the existing treehouse/no-mistakes/tasks-axi notes so the header remains a complete contract of the script's output lines.

✅ **Test** - passed

✅ No issues found.

• bash tests/fm-bootstrap.test.sh — full suite, 22/22 tests pass including new test_chromium_binary_detection (missing/present/each alternate name)
• Manual CLI run of bin/fm-bootstrap.sh (not via test harness) with a fake toolchain and no chromium-family binary on PATH: real output includes MISSING: chromium (install: npx --yes playwright install-deps chromium)
• Same manual run after adding a chromium-browser stub to PATH: the MISSING: chromium line disappears while unrelated MISSING lines (treehouse, no-mistakes, tasks-axi, quota-axi) are unchanged
• Confirmed no chromium/chromium-browser/google-chrome/google-chrome-stable exists on this machine's real PATH, so Scenario A reflects genuine (non-stubbed) absence
• git status --porcelain after testing — worktree left clean, no stray artifacts

⚠️ **Document** - 1 info

• ℹ️ docs/configuration.md's universal-toolchain list (line 237) still doesn't mention chromium as a chrome-devtools-axi dependency; this change intentionally leaves that to the still-open PR docs: document Chromium binary and shared-lib deps for chrome-devtools-axi #704, which owns that doc per the stated intent, so no edit was made here.

✅ **Lint** - passed

✅ No issues found.

✅ **Push** - passed

✅ No issues found.

[Freudator86]

Closing this ourselves. The gap it addresses is real - bootstrap never checked for a browser - but
the change tests the wrong capability and its remedy cannot clear the line it prints.

1. Wrong predicate. It probes four binary names on PATH. The consumer, chrome-devtools-axi,
   does not resolve a binary by name - it resolves a Chrome channel, and it also honours
   CHROME_DEVTOOLS_AXI_BROWSER_URL and an auto-connect setting, so a host with a perfectly working
   remote browser would still be reported as missing.
2. Wrong remedy. The suggested command installs operating-system dependencies, not a browser. A
   person who runs it sees success and still has no browser.
3. Unclearable blocker. It emits an unconditional missing-tool line that blocks dispatch, and its
   own printed fix can never satisfy the check.

All ten checks pass on this PR, which is worth stating plainly: green means the checks ran, not that
the change is correct.

A correct successor is a different change and belongs with the tool rather than here: a capability
probe owned by chrome-devtools-axi that reports what it can actually reach, consumed by bootstrap,
honouring the remote-browser settings. That is gated on the tool exposing such a probe, so it is not
a rewrite of this diff.