feat(solo/stdlib): string-keyed Map/dict builtins

[hyperpolymath]

What

Implements the highest-leverage remaining Solo Phase-2 stdlib gap: string-keyed maps.

Adds 7 builtins backed by the existing Value::Record(HashMap<String, Value>) representation (no new Value variant, no checker type-table change — same approach as the already-landed fs_*/format/env_args builtins):

builtin	signature	notes
map_new()	-> Record	empty map
map_set(m, k, v)	-> Record	immutable; returns a fresh map (overwrites existing key)
map_get(m, k)	-> value	errors (FieldNotFound) if absent
map_has(m, k)	-> Bool	membership test
map_keys(m)	-> Array<String>	sorted for deterministic tooling output
map_remove(m, k)	-> Record	immutable; no-op if absent
map_len(m)	-> Int	entry count

Mutation builtins follow the same immutable convention as push (clone + return new).

Why

Value::Record was only reachable through static, syntax-level field identifiers (eval_field). Tooling needs dynamic / computed string keys for config tables, lookup tables, and JSON-shaped data. This is also the natural object substrate for the follow-up json_parse/json_stringify work (#47), per the tracker's suggested order (Map → JSON → date).

Validation

• examples/map.my runs and produces exactly its documented expected output.
• New integration regression test test_eval_map_builtins (exercises new/set/overwrite/get/remove/len + immutability of the source map).
• Full integration suite: 16 passed, 0 failed.
• Touched files are rustfmt-clean. (Pre-existing fmt drift elsewhere in stdlib.rs left untouched — out of scope.)

Scope notes

vscode-extension/package-lock.json (pre-existing untracked file) deliberately not included.

Refs #45
Refs #46

🤖 Generated with Claude Code

[github-actions]

🔍 Hypatia Security Scan

Findings: 35 issues detected

Severity	Count
🔴 Critical	6
🟠 High	11
🟡 Medium	18

⚠️ Action Required: Critical security issues found!

View findings

[
  {
    "reason": "Issue in quality.yml",
    "type": "missing_workflow",
    "file": "quality.yml",
    "action": "create",
    "rule_module": "workflow_audit",
    "severity": "high"
  },
  {
    "reason": "Issue in security-policy.yml",
    "type": "missing_workflow",
    "file": "security-policy.yml",
    "action": "create",
    "rule_module": "workflow_audit",
    "severity": "medium"
  },
  {
    "reason": "Action hyperpolymath/standards/.github/workflows/governance-reusable.yml@main needs attention",
    "type": "unpinned_action",
    "file": "governance.yml",
    "action": "pin_sha",
    "rule_module": "workflow_audit",
    "severity": "high"
  },
  {
    "reason": "unwrap_or(0) with dangerous default (1 occurrences, CWE-754)",
    "type": "unwrap_dangerous_default",
    "file": "/home/runner/work/my-lang/my-lang/_exploratory/me-scaffolding/crates/parser/src/lib.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "critical"
  },
  {
    "reason": "expect() in hot path (80 occurrences, CWE-754)",
    "type": "expect_in_hot_path",
    "file": "/home/runner/work/my-lang/my-lang/_exploratory/me-scaffolding/crates/parser/src/lib.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "medium"
  },
  {
    "reason": "unwrap() without prior check -- DoS via panic (1 occurrences, CWE-754)",
    "type": "unwrap_without_check",
    "file": "/home/runner/work/my-lang/my-lang/my-ssg/src/generator.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "high"
  },
  {
    "reason": "expect() in hot path (5 occurrences, CWE-754)",
    "type": "expect_in_hot_path",
    "file": "/home/runner/work/my-lang/my-lang/crates/my-mir/src/lib.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "medium"
  },
  {
    "reason": "unwrap() without prior check -- DoS via panic (26 occurrences, CWE-754)",
    "type": "unwrap_without_check",
    "file": "/home/runner/work/my-lang/my-lang/crates/my-fmt/src/lib.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "high"
  },
  {
    "reason": "unwrap() without prior check -- DoS via panic (1 occurrences, CWE-754)",
    "type": "unwrap_without_check",
    "file": "/home/runner/work/my-lang/my-lang/crates/my-hir/src/lib.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "high"
  },
  {
    "reason": "unwrap() without prior check -- DoS via panic (3 occurrences, CWE-754)",
    "type": "unwrap_without_check",
    "file": "/home/runner/work/my-lang/my-lang/crates/my-llvm/src/lib.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "high"
  }
]

Powered by Hypatia Neurosymbolic CI/CD Intelligence