Bring the wilm branch into main: endpoints plugin, agent, policies, CSV import

Ports the corporate-GitHub wilm branch onto main, keeping the two branches
separate. Thirteen upstream commits arrive with their authorship intact; the
review fixes and the portability work below are on top.

What arrives:

  endpoints plugin  - a ShopDB agent reporting endpoint state, telemetry,
                      services and interfaces, with a command channel the agent
                      long-polls. Ingest stays on the generic collector route
                      (ADR-006); the agent key is a UI-managed single-scope
                      token whose revocation is an instant kill switch.
  computers policies - Configuration and Business Policies (RMM-style), scope
                      trees validated at write time, actions checked against
                      the endpoints command allowlist. Feature-gated: every
                      route 404s while the setting is off, so enabling it can
                      never half-expose the surface.
  asset CSV import  - templates, a collector script carrying the site path, and
                      a validate-then-commit import. A plugin can own a virtual
                      column plus a post-write row hook, which is how a PC's
                      machine number becomes a controls link without a
                      hand-built relationships sheet.
  agent/            - the Windows agent and its installer.

Contract 0.21.0 -> 0.24.0, additive throughout: register_import_hook (0.22),
mint/list/revoke_service_token (0.23), collector_authorized (0.24). The stability
table had no rows for any of them and now does.

MySQL 5.6 portability. The branch stored three policy columns as sa.JSON, the
only JSON columns in the product, and 5.6 has no JSON type: the migration failed
with a bare syntax error near the word JSON. They are TEXT now, through a
JSONText type decorator, so all seventeen call sites still read and write dicts.
The convention elsewhere is already TEXT (guides.blocksjson,
geenforce.manifestjson).

Review fixes carried on top:

  - six policy GETs were jwt_required(optional=True), which authenticates a
    caller without checking anything; they require computers.view now, and six
    redundant jwt_required decorators are gone
  - the agent installer took a default BaseUrl and CollectorKey, so a mistyped
    run silently pointed an endpoint at the wrong instance; both are mandatory
    and a non-https BaseUrl throws unless -AllowInsecureHttp is passed
  - a committing CSV import wrote no audit row

Documentation: the 34 new routes are described in docs/api-inventory.json, which
is hand-maintained on purpose, and the generated spec now covers 331 paths and
477 operations across 22 surfaces. DEVELOPMENT-SETUP's 1071 troubleshooting row
said "use MySQL 8 for dev" and now gives the actual fix, including the trap that
5.6 downgrades ROW_FORMAT=DYNAMIC to Compact with a warning instead of an error.

Full suite 2123 passed, vitest 260 passed, all seventeen plugin chains migrate
clean on MySQL 5.6 and the naming, docs, parity and read-surface gates are green.

tests/test_core/test_authz.py

@@ -86,7 +86,15 @@ EXEMPT_ENDPOINTS = {'knowledgebase.track_click', 'users.update_user',
                     # GET urls and a preview must not consume a one-view link.
                     # CREATING one is permission-gated and IS swept.
                     # Justification in plugins/tools/README.md.
-                    'tools.redeem_secret'}
+                    'tools.redeem_secret',
+                    # Agent-facing command result callback. Authenticated by the
+                    # endpoints collector API key (same shape as the exempt
+                    # collector blueprint), not JWT+role: the endpoint agent has
+                    # no user account, the collector key is its credential and
+                    # kill switch. Enqueue (WebUI -> operator) IS permission-gated
+                    # on endpoints.command and IS swept. Contract in
+                    # plugins/endpoints/AGENT-CONTRACT.md section 7.
+                    'endpoints.report_command_result'}
 
 
 @pytest.fixture(autouse=True)

tests/test_core/test_public_read_surface.py

@@ -73,6 +73,16 @@ PUBLIC_ENDPOINTS = {
     # The unguessable token IS the authorisation, and the recipient of a secure
     # send has no account here.
     'tools.peek_secret',
+
+    # The endpoint agent long-polls for its next command. Authenticated inside
+    # the handler by the endpoints collector API key - the same shape as the
+    # collector blueprint - because a bay has no user session. The credential is
+    # also the channel's kill switch. Note which half is public: CLAIMING a
+    # queued command is agent-facing, while ENQUEUEING one is the actual
+    # authority and stays gated on endpoints.command, audited with the
+    # requesting user. Same reasoning as endpoints.report_command_result in
+    # tests/test_core/test_authz.py.
+    'endpoints.claim_next_command',
 }
 
 # Reads that need a LOGIN but no named permission, because the handler decides