Refresh package metadata and dev deps

Aligns repository/package messaging with a clearer Spectre reactive-primitives description in both README and package.json, and adds a dedicated "Requested by Downstream" section in TODO.md for future cross-repo requests. Also updates packageManager and bumps dev dependency versions (including @phcdevworks/spectre-manifest) to keep tooling and validation stack current.

Author: bradpotts

README.md

@@ -1,5 +1,14 @@
 # @phcdevworks/spectre-shell-signals
 
+`@phcdevworks/spectre-shell-signals` is the reactive primitives package of
+the Spectre system. It provides `signal`, `computed`, and `effect` without
+tying Spectre runtime code to a UI framework.
+
+Maintained by [PHCDevworks](https://go.phcdev.co). It is the reactive
+primitive foundation for the Spectre stack, integrated by `spectre-tokens`,
+`spectre-ui`, and `spectre-ui-astro` in `project-design`, and by
+`spectre-shell` at the app-shell layer.
+
 ## Repository Snapshot
 
 | Field | Value |

TODO.md

@@ -158,3 +158,7 @@ Steps to release:
 - Do not add async resources or query layers
 - Do not add event buses or observable streams
 - Do not add DOM binding helpers or rendering lifecycle
+
+## Requested by Downstream
+
+None yet.