chore(config): harden shared agent rules

rules/01-session.md

@@ -10,4 +10,4 @@
 - Use `MEMORY.md` in that directory as the index (one line per entry pointing to a file)
 - Memory files use frontmatter: `name`, `description`, `type` (user/feedback/project/reference)
 - Commit `memory/` with the repo so memory persists across machines and sessions
-- Tool-specific runtime memory (for example `.claude/agent-memory/`) is optional and does not replace `memory/` as the project source of truth
+- Tool-specific runtime memory (for example `.claude/agent-memory/`) is supplemental and MUST NOT replace `memory/` as the project source of truth

rules/04-tools.md

@@ -1,17 +1,33 @@
 # Tool & Approach Philosophy
 
-- Prefer tools and solutions that are declarative and reproducible over imperative one-offs
+- Use tools and solutions that are declarative and reproducible over imperative one-offs
 - Portability across dev environments is a first-class concern — avoid hardcoding machine-specific paths or assumptions
-- The right tool for the job is the right tool — no language/framework bias, but favor things that can be version-pinned and reproduced
+- The right tool for the job is the right tool — no language/framework bias, and prioritize tools that are version-pinned and reproducible
+
+# Nix
+
+- Nix is the meta package manager on all systems — assume it is available even on non-NixOS Linux
+- Use a project-level `flake.nix` as the canonical way to define dev environments, build systems, and scripts
+- Dev environments go in `devShells`, project scripts/tools go in `packages` or as `apps` within the flake
+- Never suggest `apt`, `brew`, `pip install --user`, `npm install -g`, or other imperative global installs — reach for `nix shell`, `nix run`, or the project devshell instead
+- Use `nix run` for one-off tool invocations and `nix develop` (or `direnv` + `use flake`) for persistent dev shells
+- Binaries and tools introduced to a project MUST be pinned and run through Nix, not assumed to be on `$PATH` from the host
+- Flakes are the required interface — avoid legacy `nix-env` or channel-based patterns
+
+# Developer Workflows
+
+- When scaffolding a project, you MUST include `just` as standard developer tooling and make it the user-facing UX for common development workflows
+- Commonly run development workflows MUST be wired into `just` recipes as the user-facing entrypoints
+- Temporary artifacts created during work MUST be cleaned up before completion unless the user explicitly asked to keep them
 
 # Parallelism
 
 - Always parallelize independent work — tool calls, file reads, searches
 - When a task has components that don't depend on each other, run them concurrently by default
-- Sequential execution should be the exception, not the default
+- Sequential execution is allowed only when required by dependencies or operational constraints (tool/runtime limits, contention, staged validation)
 
 # Context Management
 
 - Use subagents for exploratory reads and investigations to keep the main context clean
-- Prefer scoped file reads (offset/limit) over reading entire large files
+- Use scoped file reads (offset/limit) over reading entire large files
 - When a task is complete or the topic shifts significantly, suggest clearing context or starting a new session

rules/05-verification.md

@@ -2,7 +2,7 @@
 
 - After making changes, run relevant tests or build commands to verify correctness before reporting success
 - If no tests exist for the changed code, say so rather than silently assuming it works
-- Prefer running single targeted tests over the full suite unless asked otherwise
+- Run single targeted tests by default; run the full suite when requested or when targeted coverage is insufficient
 
 # When Things Go Wrong
 

rules/06-nix.md

@@ -1,9 +0,0 @@
-# Nix
-
-- Nix is the preferred meta package manager on all systems — assume it is available even on non-NixOS Linux
-- Always prefer a project-level `flake.nix` as the canonical way to define dev environments, build systems, and scripts
-- Dev environments go in `devShells`, project scripts/tools go in `packages` or as `apps` within the flake
-- Never suggest `apt`, `brew`, `pip install --user`, `npm install -g`, or other imperative global installs — reach for `nix shell`, `nix run`, or the project devshell instead
-- Prefer `nix run` for one-off tool invocations and `nix develop` (or `direnv` + `use flake`) for persistent dev shells
-- Binaries and tools introduced to a project should be pinned and run through Nix, not assumed to be on `$PATH` from the host
-- Flakes are the preferred interface — avoid legacy `nix-env` or channel-based patterns

rules/07-research.md

@@ -2,4 +2,4 @@
 
 - Before implementing a solution, research it — read relevant documentation, search for existing patterns, check official sources
 - Do not reason from first principles when documentation or prior art exists
-- Prefer verified answers over confident guesses
+- Use verified answers over confident guesses