- add install-flex: single curl | bash installer that clones the flex
  branch, builds the binary, writes the AWS SSO profile, writes
  ~/.config/opencode/opencode.json, and appends opencode-work() to
  the user's shell rc file; all steps are idempotent
- hardcode SSO start URL and us-east-2 SSO region; prompt only for
  account ID and preferred AWS region
- correct sso_role_name from AdministratorAccess to ClaudeCodeAccess
- fix opencode-work(): replace undeclared \${opencode_args[@]} with
  "\$@", replace hardcoded path and arch with runtime uname detection
- add Quick Install section to LOCAL_AWS_SETUP.md

…B fragmentation

Without this, every build bakes the current git branch name as the installation
channel, causing OpenCode to open a new empty SQLite database each time you
rebuild from a different branch (opencode-chore-bolster-install.db,
opencode-feat-mcp-awareness.db, etc). Setting OPENCODE_CHANNEL=flex means all
Flexion fork builds share opencode-flex.db regardless of which branch was built.

…unners

Blacksmith's ubuntu-2404 runners run on ARM64 hardware (RUNNER_ARCH=ARM64).
The previous action only built an explicit bun download URL for X64, so ARM64
fell through to oven-sh/setup-bun@v2's default path which downloads
bun-linux-aarch64.zip and extracts it via the system unzip command. Blacksmith's
ARM64 Ubuntu image doesn't pre-install unzip, causing all e2e and unit CI jobs
to fail at the Setup Bun step.

Two changes:
- Add a Linux step that installs unzip if not already present (direct fix)
- Rewrite the URL construction with case/esac covering both X64 and ARM64 for
  all OS variants, replacing the x64-only if block (architecture fix)

…ion on ARM64

tree-sitter-powershell builds a native addon via node-gyp during bun install.
Blacksmith ARM64 runners don't pre-install make or g++, so the build fails with:

  gyp ERR! not found: make

Extend the prerequisite step to also check for make and install build-essential
(which provides make + g++) when missing, alongside the existing unzip check.

…in test timeouts

Plugin integration tests (auth-override, plugin config providers) each create a
fresh temp dir and trigger @npmcli/arborist to install @opencode-ai/plugin from
the npm registry. On Blacksmith ARM64, this network fetch takes 10-30 s per
test, consistently hitting the 30 s bun test timeout.

Two changes to the unit job in test.yml:
- Cache ~/.npm across runs so arborist finds tarballs locally on repeat runs
- Pre-warm step: npm install @opencode-ai/plugin once before tests run, which
  populates ~/.npm so arborist's per-test installs resolve from cache (~0.5 s)
  rather than the network (~10-30 s)

…t timeout

Root cause of all 7 test timeouts:

  config.ts fires a background @npmcli/arborist.reify() for @opencode-ai/plugin
  in every .opencode/ directory it discovers. plugin/index.ts and tool/registry.ts
  then call waitForDependencies() which joins that fiber before loading plugins
  or custom tools. On Blacksmith ARM64, a cold arborist fetch takes 10-30 s per
  test. Running in parallel across a 4-vCPU runner saturates CPU/IO and starves
  even unrelated tests (session.processor, snapshot.revert) past their 30 s limit.

Fixes:
  - flag.ts: add OPENCODE_DISABLE_PLUGIN_DEPS_INSTALL flag
  - config.ts: guard the npmSvc.install() + deps.push() block with the new flag
  - preload.ts: set OPENCODE_DISABLE_PLUGIN_DEPS_INSTALL=true for all tests
    (safe: bun resolves @opencode-ai/plugin from the workspace node_modules;
    tests do not author plugins that import the SDK at runtime)
  - snapshot.test.ts: raise timeout on the 280-file revert test to 60 s
    (git operations across 280 files can push past 30 s on ARM64)

Blacksmith ARM64 runner subprocess startup overhead can consume 2-3 s,
pushing the 'loop waits while shell runs' test past its 3 s failsafe.
The test validates ordering (loop waits while shell is running), not wall
time, so a larger timeout doesn't change what is being tested.