chore(openspec): drop 9 superseded proposals + 11 stub archive files

Drop 9 batch proposals that are superseded by the boocode-lift-analysis
(boocontext-audit, conductor upgrades, self-healing/verify-gate skills):
add-3tier-memory, import-llm-evaluator, import-pregel-engine, plugin-platform,
conductor-evolution, code-intelligence-upgrade, dev-workflow, ui-overhaul,
agent-reliability.

Delete 11 stub archive files (49-66B each, 'Status: Shipped. Archived.' only)
that provide zero documentation value over the existing CHANGELOG.md + git tags.

openspec/changes/archived/2026-06-07-eval-sandbox-agent-runtime/specs/sandbox-filesystem/spec.md

@@ -0,0 +1,50 @@
+## ADDED Requirements
+
+### Requirement: Filesystem API matching node:fs/promises
+
+The system SHALL provide `sandbox.fs` implementing the Node.js `fs/promises` API:
+
+- `readFile(path, encoding?)` → `Buffer | string`
+- `writeFile(path, data)` → `void`
+- `appendFile(path, data)` → `void`
+- `mkdir(path, { recursive? })` → `void`
+- `readdir(path, { withFileTypes? })` → `string[] | Dirent[]`
+- `stat(path)` / `lstat(path)` → `Stats`
+- `unlink(path)`, `rm(path, { recursive?, force? })`, `rmdir(path)` → `void`
+- `rename(oldPath, newPath)` → `void`
+- `copyFile(src, dest)` → `void`
+- `chmod(path, mode)`, `chown(path, uid, gid)` → `void`
+- `symlink(target, path)`, `readlink(path)` → `void`
+- `realpath(path)`, `truncate(path, len?)` → `void`
+- `mkdtemp(prefix)` → `string`
+- `access(path)`, `exists(path)` → `boolean`
+
+#### Scenario: ReadFile returns correct content
+
+- **WHEN** `sandbox.fs.readFile("/etc/hostname", "utf8")` is called
+- **THEN** it SHALL return the file content as a string
+
+#### Scenario: WriteFile creates new file
+
+- **WHEN** `sandbox.fs.writeFile("/tmp/test.txt", "hello")` is called
+- **THEN** subsequent `sandbox.fs.readFile("/tmp/test.txt", "utf8")` SHALL return `"hello"`
+
+#### Scenario: Readdir lists directory contents
+
+- **WHEN** `sandbox.fs.readdir("/")` is called
+- **THEN** it SHALL return an array of filenames
+
+#### Scenario: Stat returns file metadata
+
+- **WHEN** `sandbox.fs.stat("/etc/hostname")` is called
+- **THEN** it SHALL return a `Stats`-compatible object with `size`, `isFile()`, `isDirectory()`, `mode`, `uid`, `gid`, `mtime`, etc.
+
+#### Scenario: Mkdir creates intermediate directories
+
+- **WHEN** `sandbox.fs.mkdir("/tmp/a/b/c", { recursive: true })` is called
+- **THEN** the directory `/tmp/a/b/c` SHALL exist
+
+#### Scenario: Exists returns false for missing files
+
+- **WHEN** `sandbox.fs.exists("/nonexistent")` is called
+- **THEN** it SHALL return `false`