Harden report output publication

docs/internal/app-orchestration.md

@@ -7,9 +7,9 @@ is owned by the [CLI reference](../cli.md) and [operations guide](../operations.
 
 ## Single-Report Flow
 
-`GenerateDetailed` resolves the requested report and output destination before initializing an optional explicit debug writer. An explicit output file wins; otherwise the configured output directory is used, falling back to the captured working directory. Output preflight validates the final filename and the bounded same-directory temporary form without creating a missing parent. It then validates the report's generated-text catalog binding, exact Promptkit prompt, and selected profile before collecting weather data. The resolved profile, backend, and model are carried in the active result.
+`GenerateDetailed` resolves the requested report and output destination before initializing an optional explicit debug writer. An explicit output file wins; otherwise the configured output directory is used, falling back to the captured working directory. Output preflight validates the final filename, permits only an absent or regular final destination, and validates the bounded same-directory temporary form without creating a missing parent. It then validates the report's generated-text catalog binding, exact Promptkit prompt, and selected profile before collecting weather data. The resolved profile, backend, and model are carried in the active result.
 
-The workflow builds facts, a module snapshot, briefing metadata, and the YAML prompt package in memory. It executes Promptkit only against the inspected prompt and profile, reconciles the preparation callback and completed result with that identity and the prepared report schema, validates the returned generated text, builds a render context, and renders Markdown. `fileutil` atomically writes the completed Markdown to the selected output path. Only after that write succeeds does single-report notification run.
+The workflow builds facts, a module snapshot, briefing metadata, and the YAML prompt package in memory. It executes Promptkit only against the inspected prompt and profile, reconciles the preparation callback and completed result with that identity and the prepared report schema, validates the returned generated text, builds a render context, and renders Markdown. `fileutil` writes the completed Markdown through a same-directory temporary file, rechecks the final destination and context after close and immediately before the atomic rename. Only after that write succeeds does single-report notification run.
 
 Failures return an active partial result with safe identity, profile, warning, validation, debug, and output information when available. After rendering and immediately before publication, the workflow checks for cancellation or deadline expiry. Any failure before publication leaves an existing destination unchanged. A notification failure retains the newly published output.
 

docs/operations.md

@@ -40,7 +40,11 @@ Weatherreporter validates the final output filename before prompt inspection or
 weather collection. A valid long filename is published through a short,
 same-directory temporary sibling, so temporary naming does not shorten the
 operator-selected destination. A rejected filename does not create a missing
-parent directory.
+parent directory. The final destination itself must be absent or a regular
+file: symlinks, directories, named pipes, sockets, and other special objects
+are rejected before prompt inspection or weather collection. The destination is
+checked again immediately before the atomic replacement; cancellation or a
+deadline at that point leaves the prior report unchanged and skips notification.
 
 `SIGINT` and `SIGTERM` request orderly cancellation of an active action. The
 command lets cancellation and related cleanup finish before it exits; use the

docs/policy/architecture.md

@@ -72,6 +72,9 @@ directly.
   pre-publication failure, including cancellation observed immediately before
   publication, does not replace an existing destination; a notification failure
   does not remove a newly published output.
+- A single-report final destination is either absent or a regular file.
+  Symlinks and special filesystem objects are rejected during preflight and
+  rechecked immediately before the atomic replacement.
 - Configuration or explicit CLI input selects that operator-owned destination;
   it does not create an application-owned state boundary.
 - Comparison bundles are flat, versioned operator outputs. Their guarded