feat(presets): resolve constitution templates at command time (#3984)

* feat(presets): resolve constitutions at command time

Gate install-time constitution materialization behind the constitution-sync preset while preserving one-time init seeding and authored-file safeguards.

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84

* fix(presets): emit composed template content

Add a machine-readable preset resolve mode backed by PresetResolver.resolve_content and require the constitution command to consume it.

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84

* fix(presets): unify runtime template composition

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84

* fix(presets): secure runtime template resolution

Align runtime resolution across script variants, validate registry path components, and honor canonical extension ordering and convention paths.

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* fix(presets): align runtime priority semantics

Normalize and tie-break preset priorities consistently across script variants, and preserve template bytes when Python materializes generated files.

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* fix(presets): stop at effective template base

Avoid parsing irrelevant lower layers once resolution reaches a replace base, and decode raw bytes so Python preserves source line endings.

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* fix(presets): align extension template resolution

Support root-level extension templates across runtime resolvers, fail safely when Bash cannot parse an extension registry, and validate requested templates in every prerequisite output mode.

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* fix(presets): resolve dotted command identifiers

Route safe dotted names through command resolution, correct traversal coverage, and make Windows CI text decoding explicit.

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Avoid orphan feature directories on template errors

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

* Align malformed preset manifest handling

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

* Complete runtime resolver parity

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

* Fail closed on resolver input errors

Assisted-by: GitHub Copilot (model: GPT-5.6 Sol, autonomous)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

* Force UTF-8 and full manifest validation

Force UTF-8 decoding for registry and manifest reads in the Bash and
PowerShell embedded-Python parsers so resolution no longer depends on the
process locale, and validate every manifest template entry's required
fields, type, and strategy consistent with the canonical PresetManifest.

Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous)
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

* Fail closed on empty manifests and corrupt registries

Reject manifests missing the provides/templates sections or declaring an
empty template list in all three runtime resolvers, matching the canonical
PresetManifest which treats those as invalid instead of silently degrading a
composing layer to a convention `replace` lookup.

Make a corrupt or unreadable extension registry fail closed in Bash,
PowerShell, and Python instead of swallowing the error and treating every
on-disk extension directory as unregistered-and-enabled, which could activate
a disabled extension.

Read the preset and extension registries as explicit UTF-8 in the PowerShell
resolver so priority/enabled-state decoding no longer depends on the process
code page under Windows PowerShell 5.1.

Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous)
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

* fix(presets): fail closed when extension registry is not a regular file

The Bash and Python resolvers used is_file()/`-f` to gate reading the
extension `.registry`, which returns false for a directory or a broken
symlink at that path. In those cases the resolvers treated the registry
as absent and scanned every on-disk extension directory as unregistered
and enabled — a fail-open path. Detect any filesystem entry at the
registry path (including broken symlinks) and reject unless it is a
readable regular file. PowerShell now rejects a non-leaf entry explicitly
for parity. Adds directory- and broken-symlink parity regressions.

Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous)
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

* fix(presets): fail closed on corrupt registry in canonical resolver and PowerShell

Two remaining fail-open paths for an invalid extension registry:

- The canonical PresetResolver enumerated extensions through
  ExtensionRegistry, whose _load() normalizes a corrupt or unreadable
  registry to an empty mapping. The directory scan then admitted every
  on-disk extension directory as unregistered-and-enabled, so a corrupt
  registry could still supply constitution content at init and through
  constitution-sync materialization. Add a non-invasive is_corrupt()
  probe (recovery behavior for install/enable/disable is unchanged) and
  raise from _get_all_extensions_by_priority() when the registry exists
  but is invalid. _load() now also recovers from OSError/UnicodeDecodeError
  so a directory or unreadable registry no longer crashes construction.

- The PowerShell resolver gated the registry read with Test-Path, which
  returns false for a dangling symlink on Windows, letting a broken
  .registry symlink bypass the guard and enable every on-disk extension.
  Detect the entry via directory enumeration (which observes a broken
  symlink) and reject it unless it is a readable regular file.

Adds canonical corrupt/directory-registry regressions and extends the
broken-symlink parity test to PowerShell.

Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous)
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

* fix(presets): detect dangling registry symlink in ExtensionRegistry.is_corrupt

is_corrupt() gated on Path.exists(), which follows symlinks and returns
False for a dangling .registry symlink — so the canonical PresetResolver
treated it as an absent registry and fell back to scanning every on-disk
extension directory as unregistered-and-enabled, reopening the fail-open
path this guard closes. Detect lexical existence with os.path.lexists and
require a regular file before parsing, so a broken symlink (or directory)
is reported corrupt and resolution fails closed. Adds a canonical
broken-symlink regression alongside the directory case.

Assisted-by: GitHub Copilot (model: claude-opus-4.8, autonomous)
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

---------

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 7dbce70f-80c6-4e14-a30d-78cb358bcb84
Copilot-Session: 3158e06f-95df-4e3a-843f-f159a35aa30c

scripts/python/setup_tasks.py

@@ -10,17 +10,21 @@ from pathlib import Path
 try:
     from common import (
         FeaturePaths,
+        TemplateResolutionError,
         format_speckit_command,
         get_feature_paths,
         resolve_template,
+        resolve_template_content,
     )
 except ImportError:  # pragma: no cover - direct execution from unusual cwd
     sys.path.insert(0, str(Path(__file__).resolve().parent))
     from common import (
         FeaturePaths,
+        TemplateResolutionError,
         format_speckit_command,
         get_feature_paths,
         resolve_template,
+        resolve_template_content,
     )
 
 
@@ -120,8 +124,14 @@ def main(argv: list[str] | None = None) -> int:
 
     docs = _available_docs(paths)
 
-    tasks_template = resolve_template("tasks-template", paths.repo_root)
-    if tasks_template is None or not tasks_template.is_file():
+    try:
+        tasks_template_content = resolve_template_content(
+            "tasks-template", paths.repo_root
+        )
+    except TemplateResolutionError as exc:
+        print(f"ERROR: {exc}", file=sys.stderr)
+        return 1
+    if tasks_template_content is None:
         print(
             "ERROR: Could not resolve required tasks-template from the template "
             f"override stack for {paths.repo_root}",
@@ -138,18 +148,21 @@ def main(argv: list[str] | None = None) -> int:
         return 1
 
     if json_mode:
+        tasks_template = resolve_template("tasks-template", paths.repo_root)
         sys.stdout.write(
             _json_line(
                 {
                     "FEATURE_DIR": str(paths.feature_dir),
                     "AVAILABLE_DOCS": docs,
-                    "TASKS_TEMPLATE": str(tasks_template),
+                    "TASKS_TEMPLATE": str(tasks_template) if tasks_template else "",
+                    "TASKS_TEMPLATE_CONTENT": tasks_template_content,
                 }
             )
         )
     else:
+        tasks_template = resolve_template("tasks-template", paths.repo_root)
         print(f"FEATURE_DIR: {paths.feature_dir}")
-        print(f"TASKS_TEMPLATE: {tasks_template}")
+        print(f"TASKS_TEMPLATE: {tasks_template or 'not found'}")
         print("AVAILABLE_DOCS:")
         _check_file(paths.research, "research.md")
         _check_file(paths.data_model, "data-model.md")