refactor: make src/llm/ self-contained for crate extraction (#767)

* refactor: make src/llm/ self-contained for crate extraction

Move LlmError, LLM config types, and OAuth callback helpers into
src/llm/ so the module has zero `use crate::` imports outside of
crate::llm. This prepares the module for extraction into a standalone
workspace crate.

- Move LlmError enum from src/error.rs to src/llm/error.rs
- Move LlmConfig, NearAiConfig, RegistryProviderConfig, BedrockConfig,
  CacheRetention, OAUTH_PLACEHOLDER from src/config/llm.rs to
  src/llm/config.rs
- Move OAuth callback utilities (callback_url, bind_callback_listener,
  wait_for_callback, landing_html, etc.) from src/cli/oauth_defaults.rs
  to src/llm/oauth_helpers.rs
- Remove session.rs dependency on crate::bootstrap (inline default path)
- Add cache_retention field to RegistryProviderConfig, resolve from env
  in config/llm.rs instead of reading env var in llm/mod.rs
- Add Check 6 to scripts/check-boundaries.sh enforcing LLM isolation
- All original locations re-export for backward compatibility

[skip-regression-check]

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: fix formatting

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: address PR #767 review — session path bug and boundary check

1. Fix SessionConfig::default() usage in setup wizard: the fallback at
   wizard.rs:995 now constructs SessionConfig with the real
   default_session_path() instead of a relative "session.json", which
   would write auth tokens to the CWD instead of ~/.ironclaw/.

2. Widen check-boundaries.sh Check 6 to catch all `crate::` references
   (not just `use crate::` imports). Pre-existing inline references
   (16 occurrences) are reported as warnings; only new `use crate::`
   imports are hard violations.

[skip-regression-check]

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: address PR #767 review and audit findings in src/llm/

PR review fixes:
- Reject wildcard addresses (0.0.0.0, ::) in OAuth callback listener
  to prevent session token exposure on all interfaces
- Fix boundary check comment-stripping that could hide real violations
  (use sed to strip inline comments before matching)

Audit fixes:
- Fix UTF-8 byte-index slicing panic in recording.rs hint extraction
- Add effective_model_name() delegation to RetryProvider and
  SmartRoutingProvider for consistency with other wrappers
- Add calculate_cost() delegation to CachedProvider and RecordingLlm
- Deduplicate retry loop logic in RetryProvider via generic helper
- Replace hardcoded /tmp path in recording tests with tempfile

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

scripts/check-boundaries.sh

@@ -209,6 +209,56 @@ else
 fi
 echo
 
+# --------------------------------------------------------------------------
+# Check 6: LLM module isolation — no imports from other crate modules
+# --------------------------------------------------------------------------
+# src/llm/ should only import from:
+#   - crate::llm (self-references)
+#   - external crates (no crate:: prefix)
+# It must NOT import from crate::agent, crate::tools, crate::channels,
+# crate::safety, crate::config, crate::bootstrap, crate::cli, crate::db,
+# crate::workspace, crate::worker, crate::orchestrator, crate::skills,
+# crate::hooks, crate::setup, crate::context, etc.
+#
+# Test-only imports (crate::testing) are excluded since they don't affect
+# the runtime dependency graph and won't exist in the extracted crate.
+# --------------------------------------------------------------------------
+
+echo "--- Check 6: LLM module isolation ---"
+
+# Match any `crate::` reference (use-imports AND inline paths) that isn't
+# crate::llm or crate::testing.  Filter out comments.
+# We strip inline comments (everything after //) with sed before checking,
+# so a line like `real_code(crate::foo); // crate::llm` is still caught.
+results=$(grep -rn 'crate::' src/llm/ \
+    --include='*.rs' \
+    | grep -v '^\s*//' \
+    | sed 's|//.*||' \
+    | grep 'crate::' \
+    | grep -v 'crate::llm' \
+    | grep -v 'crate::testing' \
+    || true)
+
+if [ -n "$results" ]; then
+    count=$(echo "$results" | wc -l | tr -d ' ')
+    echo "WARNING: src/llm/ has $count reference(s) to modules outside crate::llm:"
+    echo "$results"
+    echo
+    echo "(These are pre-existing; fix them before extracting the crate.)"
+    echo "(New 'use crate::' imports are hard violations — see below.)"
+    echo
+    # Hard-fail only on new `use crate::` imports (easy to avoid in new code).
+    use_imports=$(echo "$results" | grep '^[^:]*:.*use crate::' || true)
+    if [ -n "$use_imports" ]; then
+        echo "HARD VIOLATION: new 'use crate::' imports in src/llm/:"
+        echo "$use_imports"
+        violations=$((violations + 1))
+    fi
+else
+    echo "OK"
+fi
+echo
+
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 # Summary
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