fix(components): use identity equality for ComponentOwned lifecycle objects (#6776)

[chiliec]

What

Closes #6776.

ComponentOwned and its subclasses Hook and ObservableSubscription are lifecycle objects tracked in lists and matched by identity (in, list.remove). They are dataclasses whose only declared fields are InitVars (owner, observable), so the auto-generated __eq__ compares no fields — making every instance compare equal to every other.

In Component._detach_observable_subscription:

if subscription in self._state.observable_subscriptions:
    subscription.dispose()
    self._state.observable_subscriptions.remove(subscription)

subscription in ... matches a different subscription, and .remove() deletes the wrong one — so the subscription that should have been detached is leaked (the memory/subscription leak in the issue). The same collision affects Hook, which is stored per render slot and compared by identity.

Fix

Set eq=False on ComponentOwned, Hook, and ObservableSubscription so they fall back to object's identity-based __eq__/__hash__. Each subclass is decorated with @dataclass, which regenerates __eq__, so the flag is applied to all three.

Reproduction (before the fix)

s1 = ObservableSubscription(owner, obs_a)
s2 = ObservableSubscription(owner, obs_b)
s1 == s2          # True  ← distinct subscriptions compare equal
s2 in [s1]        # True  ← wrong-match
[s1, s2].remove(s2)  # removes s1 instead of s2

After the fix all three return the correct result (False, False, removes s2).

Tests

Added tests/test_component_owned_identity.py (3 cases): ComponentOwned, Hook, and ObservableSubscription each use identity equality and behave correctly under in/list.remove.

Verified RED→GREEN: reverting the three classes to plain @dataclass fails all three new tests with assert ObservableSubscription() != ObservableSubscription(); with eq=False they pass.

Validation (real results, Python 3.11, pytest)

• tests/test_component_owned_identity.py: 3/3 pass
• test_observable.py, test_component_renderer.py, test_component_diff.py, test_component_effects.py: all pass (16/16 together with the new file) — no regressions.

(Some unrelated test modules fail to collect in my environment due to a missing optional msgpack dependency; this happens identically on a clean main checkout and is unrelated to this change.)

Summary by Sourcery

Use identity equality for component-owned lifecycle objects to prevent incorrect list operations and leaked observable subscriptions.

Bug Fixes:

• Ensure component-owned lifecycle objects use identity equality so detaching subscriptions and managing hooks cannot match or remove a different instance.

Tests:

• Add regression coverage for identity-based equality and list membership/removal across ComponentOwned, Hook, and ObservableSubscription.

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