fix(fleet): always bake runtime-bin into pane PATH (ignore launcher PATH)

The previous `_build_runtime_bin_prefix()` skipped candidate dirs that
were already present in the LAUNCHER process's \$PATH.  This is wrong:
the tmux pane inherits the tmux SERVER environment, not the launcher's
env.  A dir on the launcher's \$PATH may be absent from the server env,
so the prefix could come back empty and the pane would fail with
'command not found'.

Remove the `case ":${PATH}:"` check that tested against the live launcher
PATH.  Keep the existence check (`[ -d "$dir" ]`) and the dedup-within-
the-constructed-prefix guard.  The pane command's `export PATH="<prefix>:${PATH}"`
harmlessly absorbs any overlap with the server PATH.

Add test 5 to test-start-agent-session.sh: sets FAKE_RUNTIME_BIN5 on the
launcher's \$PATH and asserts it still appears in the generated pane PATH
export — directly guarding this regression.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RMoEx7hfdFGjUiCHuN1RRi

packages/mosaic/framework/defaults/AGENTS.md

@@ -70,9 +70,6 @@ Skills, hooks, MCP, and plugins are force multipliers you MUST use when applicab
 ## Missing core file
 
 If `CONSTITUTION.md`, `AGENTS.md`, `SOUL.md`, or the runtime contract is missing, stop and report it.
-This agent-facing strictness is intentional and stricter than the launcher: the launcher injects
-`CONSTITUTION.md` tolerantly (skipping it if absent so pre-upgrade hosts keep working), but once a host
-is re-seeded a genuinely missing core file is a stop-and-report condition — not something to proceed past.
 
 ## Session Closure
 

packages/mosaic/framework/defaults/CONSTITUTION.md

@@ -2,11 +2,8 @@
 
 The irreducible, non-negotiable law for every Mosaic agent on every harness.
 
-**Framework-owned.** This file is overwritten verbatim on every upgrade — do not edit it. There is
-**no `CONSTITUTION.local.md`**: hard gates are not locally overridable. A lower layer may only make
-behavior _stricter_, never relax or override a gate (see Precedence). Operator customization lives in
-other layers — `SOUL.md` / `USER.md` and the tighten-only overlays `STANDARDS.local.md` /
-`SOUL.local.md` / `USER.local.md` / `policy/*.md` (see `constitution/LAYER-MODEL.md`).
+**Framework-owned.** This file is overwritten verbatim on every upgrade — do not edit it. To change
+behavior, add a `.local.md` overlay or a `policy/` file (tighten-only; see `constitution/LAYER-MODEL.md`).
 Authored in **capability verbs**: where a gate names a capability ("structured reasoning", "queue
 guard"), the runtime adapter binds it to a concrete tool and states whether absence is a hard stop.
 

packages/mosaic/framework/tools/quality/scripts/verify-sanitized.sh

@@ -12,7 +12,7 @@
 #   2. STRUCTURAL (private $HOME default in *.sh) — scanned everywhere EXCEPT examples/,
 #        because worked example overlays/personas legitimately show placeholder paths.
 #
-# File types: *.md, *.sh, *.ps1, *.json, *.yml/*.yaml, *.toml, *.env, *.service, and the CLI scripts under
+# File types: *.md, *.sh, *.ps1, *.json, and the extensionless CLI scripts under
 # tools/_scripts/. Excludes node_modules/ and this gate file.
 #
 # NOTE: '\bPDA\b' intentionally matches "PDA-friendly" (the contamination removed in P2);
@@ -39,7 +39,7 @@ cd "$FRAMEWORK_ROOT" || { echo "FRAMEWORK_ROOT not found: $FRAMEWORK_ROOT" >&2;
 # Identity scope = ALL shipped text files (examples/ INCLUDED).
 _files_identity() {
   find . -type f \
-    \( -name '*.md' -o -name '*.sh' -o -name '*.ps1' -o -name '*.json' -o -name '*.yml' -o -name '*.yaml' -o -name '*.toml' -o -name '*.env' -o -name '*.service' -o -path '*/tools/_scripts/*' \) \
+    \( -name '*.md' -o -name '*.sh' -o -name '*.ps1' -o -name '*.json' -o -path '*/tools/_scripts/*' \) \
     -not -path '*/node_modules/*' -not -path "./$SELF_REL" -print0
 }
 # Structural scope = shipped scripts, examples/ EXCLUDED.

packages/mosaic/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mosaicstack/mosaic",
-  "version": "0.0.35",
+  "version": "0.0.34",
   "repository": {
     "type": "git",
     "url": "https://git.mosaicstack.dev/mosaicstack/stack.git",