feat: merge http/web_fetch tools, add tool output stash for large responses (#578)

* feat: merge http/web_fetch tools, add tool output stash for large responses

Merge `web_fetch` into `http` tool with smart approval: plain GETs (no
headers, no body) run without approval and follow redirects with SSRF
re-validation per hop; all other requests require approval as before.

Add `tool_output_stash` on JobContext so full tool outputs are preserved
before safety-layer truncation. The `json` tool gains a
`source_tool_call_id` parameter to reference stashed outputs, enabling
reliable parsing of large API responses that exceed the 100KB context
limit.

Other improvements:
- Descriptive User-Agent header using CARGO_PKG_VERSION
- Truncation now keeps partial data + hint about source_tool_call_id
- System prompt reinforces tool_calls over narration
- json tool query/stringify handle pre-parsed (non-string) data

[skip-regression-check]

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

* chore: delete dead web_fetch.rs (merged into http tool)

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

* style: fix rustfmt formatting

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

* style: rename shadowed data binding for clarity in json tool

Address PR review: rename owned `data` to `data_value` before
re-binding as `let data = &data_value` to make ownership explicit.

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

* fix(ci): mark network-dependent trace tests as #[ignore]

The weather_sf and baseball_stats tests hit live external APIs (wttr.in,
ESPN) which are unreliable in CI. Mark them #[ignore] so they don't
block the pipeline. Run locally with `--ignored` to include them.

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

* fix: replay recorded HTTP exchanges in trace tests instead of hitting live APIs

Wire ReplayingHttpInterceptor into TestRig when the trace fixture
contains http_exchanges. This replays recorded responses instead of
making live network calls, making tests deterministic and CI-stable.

Add captured HTTP responses to weather_sf.json (wttr.in) and
baseball_stats.json (ESPN API) fixtures.

Revert #[ignore] on both tests — they now run offline.

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

* fix: recover inline bracket-format tool calls from LLM text responses

When flatten_tool_messages converts tool calls to text like
`[Called tool `http` with arguments: {...}]` for NEAR AI compatibility,
the LLM sometimes echoes this format back in its text responses instead
of using proper tool_calls. Add recovery for this bracket format in
recover_tool_calls_from_content and strip it in clean_response so
users don't see raw tool call syntax.

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

---------

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

src/safety/mod.rs

@@ -47,14 +47,22 @@ impl SafetyLayer {
 
     /// Sanitize tool output before it reaches the LLM.
     pub fn sanitize_tool_output(&self, tool_name: &str, output: &str) -> SanitizedOutput {
-        // Check length limits first
+        // Check length limits — keep the beginning so the LLM has partial data
         if output.len() > self.config.max_output_length {
+            // Find a safe truncation point on a char boundary
+            let mut cut = self.config.max_output_length;
+            while cut > 0 && !output.is_char_boundary(cut) {
+                cut -= 1;
+            }
+            let truncated = &output[..cut];
+            let notice = format!(
+                "\n\n[... truncated: showing {}/{} bytes. Use the json tool with \
+                 source_tool_call_id to query the full output.]",
+                cut,
+                output.len()
+            );
             return SanitizedOutput {
-                content: format!(
-                    "[Output truncated: {} bytes exceeded maximum of {} bytes]",
-                    output.len(),
-                    self.config.max_output_length
-                ),
+                content: format!("{}{}", truncated, notice),
                 warnings: vec![InjectionWarning {
                     pattern: "output_too_large".to_string(),
                     severity: Severity::Low,