docs(agents): bring agent-facing docs in line with the R44 fix

Six docs lagged after the post-merge R44 fix added withCapture +
reported-flag.ts. They mentioned withSpan only and described the
capture story as if it were inline in use-case / controller bodies.
This commit aligns them with what shipped.

CLAUDE.md (Key Conventions):
- "Spans applied at DI bind time" → "Spans + capture composed at DI
  bind time" with the withSpan(withCapture(factory)) sandwich and the
  outermost-span ordering note.
- "Capture at throw sites only" expanded to mention the
  __sentryReported flag, the three flag-checking sites (withCapture,
  SentryLogger, RecordingLogger), and where the helper lives.

AGENTS.md (Instrumentation conventions):
- Use case + controller wrapping example shows the full sandwich.
- Capture-rules table now explicitly says "via withCapture" for use
  cases and controllers, and "flag set, withCapture bails" for the
  bubbled cases.

packages/core-shared/AGENTS.md:
- "with-span.ts" entry split into a paired with-span + with-capture
  block, including the actual sandwich code.
- New entry for reported-flag.ts explaining the helper and why
  RecordingLogger inlines the check (boundary rule).
- Barrel re-export list updated.

docs/architecture/vertical-feature-spec.md (§16):
- The bind-production line now describes the withSpan(withCapture(...))
  sandwich, the outermost-span rationale, and the bubbled-error bail.

docs/architecture/dependency-flow.md (TRACER/LOGGER subsection):
- bindAll diagram updated: real repo line annotates inline calls; use
  case + controller lines show withSpan(withCapture(...)).

docs/guides/tdd-workflow.md (Asserting spans and captures):
- Direct-injection example shows the binder sandwich.
- Capture-assertion example explains the flag-bail behaviour and
  links to the new tests/r44-no-double-capture.test.ts e2e example.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/architecture/vertical-feature-spec.md

@@ -694,7 +694,7 @@ Invoke the `superpowers:writing-plans` skill to produce a detailed, executable i
 
 - `infrastructure/repositories/<entity>.repository.ts` — constructor takes `(config, tracer, logger)` with Noop defaults; every public method's body is wrapped in `tracer.startSpan(...)` and any `catch` block calls `logger.captureException(err, { tags: { feature, repo, method } })` before re-throwing.
 - `infrastructure/repositories/<entity>.repository.mock.ts` — same constructor/wrapping shape (no catch — mocks don't originate infra errors).
-- `di/bind-production.ts` — signature `(config, tracer, logger)`. Binds TRACER + LOGGER to the feature container; constructs the real repo with tracer/logger; wraps every use case + controller via `withSpan` at bind time.
+- `di/bind-production.ts` — signature `(config, tracer, logger)`. Binds TRACER + LOGGER to the feature container; constructs the real repo with tracer/logger; wraps every use case + controller via `withSpan(withCapture(factory(deps)))` at bind time. `withSpan` is outermost so an errored span's timing reflects the capture-and-rethrow; `withCapture` honours the `__sentryReported` flag so a bubbled error from the repo isn't re-captured.
 - `di/bind-dev-seed.ts` — signature `(tracer, logger)`. Same wrapping as bind-production but with the populated mock.
 
 **Required exports (per feature root):** unchanged.